physics102’ iclicker’questions’ - physics and...

Physics 102

Iclicker Questions The most important attribute of a scientific theory is:

a) It is believed to be true by a majority of scientists. b) It has been shown to be true by observations and experiments. c) It can be proven to be false. d) It is derived by mathematical proof. e) It has stood the test of time.

How can you tell whether a bright night-sky object is a planet? A. It is brighter than other objects. B. It appears to move relative to most other objects. C. It appears in a fixed point in the night sky. D. It appears to be larger than most other objects. E. It appears to move in the opposite direction from most other objects.

In order to explain retrograde motion, the ancient Greeks introduced: A. A sun-‐centered universe. B. Epicycles. C. Elliptical orbits. D. A spinning Earth. E. They were unable to understood how that came about.

Brahe’s observations were used by Kepler to show: A. The Sun is at the center of the universe. B. The Earth is at the center of the universe. C. Stars do not move. D. Neither Ptolemy’s theory nor Copernicus’ theory was correct. E. Kepler died before Brahe was born so he couldn’t use these observations.

How did ancient Greeks such as Aristotle know that Earth is round? a. By noting that ships drop below the horizon as they go out to sea. b. Travelers reported that, in northern lands, the noontime sun is lower in the

sky. c. The shadow cast by Earth on the moon during an eclipse is the shape that

would be expected if both Earth and the moon were spherical. d. All of the above. Actually, the ancient Greeks thought that Earth is flat.

How did ancient Greeks such as Aristotle know that Earth is round? a) By noting that ships drop below the horizon as they go out to sea. b) Travelers reported that, in northern lands, the noontime sun is lower in the sky. c) The shadow cast by Earth on the moon during an eclipse is the shape that

would be expected if both Earth and the moon were spherical. d) All of the above. e) Actually, the ancient Greeks thought that Earth is flat.

In the discussion of Chapter 2, atoms are considered as tiny balls. In this simple model, how is Helium (an inert gas with one atom per molecule) gas in a box pictured?

a) Molecules tightly packed together filling the box. b) Molecules regularly placed on a lattice pattern in the box. c) Motionless molecules randomly spaced within the box. d) Molecules flying around filling the volume of the box with space between them. e) This is nonsense – Helium is an invisible gas.

In this simple model of Helium gas, what keeps the molecules flying around? a) I have no idea. b) There must be a force constantly pushing on each molecule. c) Gravity. d) Conservation of Energy. e) The second Law of Thermodynamics.

The first person credited with proposing that matter is composed of atoms was: a) Democritus. b) Aristotle. c) Dalton. d) Lavoisier. e) Newton.

5. What evidence do we have now to support the idea of the existence of atoms? a) They have been seen with powerful optical microscopes. b) The Law of Definite Proportions – elements combining chemically tend to

combine in simple ratios. c) Brownian motion. d) All of the above. e) Both B and C above.

A molecule: A. is smaller than an atom. B. is smaller than an element. C. is always made up of more than one element. D. is the smallest piece of a chemical compound. E. cannot be broken apart by chemical means.

The Sun’s mass (1,989,000,000,000,000,000,000,000,000,000 kg) would be written by a scientist as:

A. 1.989 × 1029 kg. B. 1.989 × 1030 kg. C. 1,989,000,000,000,000,000,000,000,000,000 kg. D. 2 × 1030 kg. E. too big to think about.

105 × 103 = ? A. 1015 B. 102 C. 108 D. 104 E. I thought this was a nonmathematical course.

Galileo supposedly dropped different objects off The Tower of Pisa and showed that Aristotle was wrong about falling objects. Why was this so important?

a) It showed that Aristotelian physics wasn’t correct. b) It led to Newton’s Laws. c) It was the first time someone did an experiment to test a scientific theory. d) It showed that air resistance is important when considering falling objects. e) It led to the concept of inertia.

An important contribution of Galileo was: a) He used a telescope for astronomical observations. b) He tested existing theories with experiments. c) He was able to use thought experiments to enhance his understanding. d) He considered how phenomena appear to different observers moving with

respect to each other. e) He figured out how to do quantitative measurements of objects falling because

of gravity. The Earth orbits around the Sun once a year. What keeps the Earth moving?

a) Inertia b) Gravity c) Conservation of energy d) The centrifugal force e) The Sun

What is the difference between speed and velocity? a) Speed is how fast something is moving; velocity includes both speed and

direction. b) There is no difference between them. c) Speed is measured in feet/sec while velocity is measured in meters/sec. d) Speed is how fast something is moving; velocity is how rapidly it is speeding

up or slowing down. e) Speed is an Aristotelian concept; velocity is Newtonian.

A car accelerates when: A. Its speed increases. B. Its speed decreases. C. Its direction of motion changes. D. A or B above. E. A, B, or C above.

Newton’s First Law states – “An object at rest stays at rest and an object in motion stays in motion with the same velocity (speed and direction) unless acted upon by an unbalanced force.” Newton wasn’t the first to state this law and it is contained in his second law. Why did Newton give such prominence to the first law?

A. He wanted to claim credit for it. B. He didn’t realize that Descartes had already written it down. C. He wanted to emphasize that the Aristotelian view was incorrect. D. How should I know what went through Newton’s mind? E. That’s in chapter 4 and we’re doing chapter 3.

What is acceleration? A. An increase in speed over a time interval. B. An increase or decrease in speed over a time interval. C. An increase or decrease in velocity over a time interval. D. Going faster. E. A change in velocity over a time interval.

The graph below depicts what kind of motion?

A. An object at rest. B. An object moving with a constant speed of 1 m/s. C. An object moving with a constant speed of 10 m/s. D. An object accelerating with an increasing speed. E. An object decelerating with a decreasing speed.

According to Newtonian physics, an object with no forces acting on it must A. Fall. B. Eventually come to rest. C. Be at rest. D. Either be at rest or have constant velocity. E. Be accelerated, with an unchanging acceleration.

If you are driving a car making a right-‐hand turn, why do you tend to lean into the left-‐hand door?

A. You tend to continue to go straight while the car moves towards the right.

B. Newton’s Third Law. C. Friction pushes you to the left. D. Your inertia pushes you to the left. E. The car door has it in for you.

A "force" could be best described as A. Something one body does to another body that keeps the second

body moving. B. Something one body does to another body that can cause the

second body to accelerate. C. Something that a body possesses, that enables it to keep moving. D. Something that a body possesses, that enables it to do work. E. A mystical aura that emanates after midnight from physics

laboratories. You throw a ball straight upward. After it leaves your hand, the net force on the ball is

A. directed opposite to the acceleration. B. zero. C. in the downward direction. D. in the upward direction. E. in the horizontal direction.

You throw a ball straight upward. At the instant it stops at the top of its path, the net force on the ball is


Marcia places a lead block and an iron block on the table, and hits both of them with the same force. The lead block is twice as massive as the iron block. The acceleration of the lead block is

A. four times that of the iron block. B. two times that of the iron block. C. equal to that of the iron block. D. half that of the iron block. E. a quarter of that of the iron block.

You are freely floating in distant space (no air, no gravity). A giant asteroid, many times larger than you, is at rest in front of you. You tap the boulder lightly with a small hammer. What does the boulder do?

A. It speeds up a little during the tap, but after the tap it soon slows down and comes to rest.

B. It accelerates both during and after the tap. C. It remains at rest. D. It accelerates during the tap, up to a high speed, and then keeps

moving at that speed. E. It accelerates during the tap, up to a slow speed, and then keeps

moving at that speed.

Mary pushes horizontally on a large, heavy table which is standing alone in the middle of a room, and notes that the table does not move despite the fact that she is pushing on it (see diagram). Why doesn't the table move?

A. A frictional force is also exerted by the floor on the table, and this force is equal and opposite to the pushing force.

B. The table exerts a force on Mary, and this force is equal and opposite to the pushing force.

C. Very massive objects, such as the table, are difficult to set into motion because of their large inertia.

D. The force of gravity pulls downward on the table, and this force cancels the pushing force.

E. The table pushes back on Mary with a force that is even larger than Mary's pushing force.

If you are driving a car and step hard on the brakes. Why do you tend to go forward and hit the dashboard?

a) Newton’s Third Law. b) The seat pushes you forward. c) Your inertia pushes you forward. d) The dashboard has it in for you. e) Your inertia keeps you moving forward but the dashboard, part of the

stopping car, comes towards you. A "force" could be best described as

a) Something one body does to another body that keeps the second body moving.

b) Something one body does to another body that can cause the second body to accelerate.

c) Something that a body possesses, that enables it to keep moving. d) Something that a body possesses, that enables it to do work. e) A mystical aura that emanates after midnight from physics laboratories.

You throw a ball straight upward. After it leaves your hand, the net force on the ball is a) directed opposite to the acceleration. b) Once it leaves your hand, there is no longer any force. c) in the downward direction. d) in the upward direction. e) in the horizontal direction.


a) directed opposite to the acceleration. b) zero. c) in the downward direction. d) in the upward direction. e) in the horizontal direction.

When you jump straight upwards, the force that pushes you up is: A. exerted by your legs against the ground. B. exerted by the ground against your legs. C. gravity. D. There is no force – you just jump. E. Upwards after you leave the ground.

You place a lead block and an iron block on a smooth table, and hit both of them with the same force. The lead block is twice as massive as the iron block. The acceleration of the lead block is

a) four times that of the iron block. b) two times that of the iron block. c) equal to that of the iron block. d) half that of the iron block. e) a quarter of that of the iron block.

You are freely floating in distant space (no air, no gravity). A giant asteroid, many times larger than you, is at rest in front of you. You tap the boulder lightly with a small hammer. What does the boulder do?

a) It speeds up a little during the tap, but after the tap it soon slows down and comes to rest.

b) It accelerates both during and after the tap. c) It remains at rest. d) It accelerates during the tap, up to a high speed, and then keeps moving at

that speed. e) It accelerates during the tap, up to a slow speed, and then keeps moving at

that speed. Mary pushes horizontally on a large, heavy table which is standing alone in the middle of a room, and notes that the table does not move despite the fact that she is pushing on it. Why doesn't the table move?

a) A frictional force is also exerted by the floor on the table, and this force is equal and opposite to the pushing force.

b) The table exerts a force on Mary, and this force is equal and opposite to the pushing force.

c) Very massive objects, such as the table, are difficult to set into motion because of their large inertia.

d) The force of gravity pulls downward on the table, and this force cancels the pushing force.

e) The table pushes back on Mary with a force that is even larger than Mary's pushing force.

I stand on a scale in the gym and it gives my weight as 70 kg. What is my mass? A. 70 kg. B. 70 x 10 m/s2 = 700 kg. C. 70 /10 m/s2 = 7 kg. D. 70 x [10 m/s2 ]2= 7000 kg. E. You can’t tell from the information given.

I have a mass of 70 kg. How much do I weigh? A. 700 kg. B. 700 nt C. 700 lbs D. 7 nt. E. You can’t tell from the information given.

I have a mass of 60 kg. What is my mass on the Moon where the acceleration due to gravity is 1/6th of that on Earth?

A. 60 kg B. 60 nt C. 6 kg D. 6 nt E. You can’t tell from the information given.

Joe weighs 180 lbs. How much does he weigh on the Moon where the acceleration due to gravity is 1/6th of that on Earth?

A. 180 lbs. B. 30 lbs C. 180 x 6 = 1080 lbs D. 30 kg. E. You can’t tell from the information given.

You are the head of a train workers union and one of your members, having taken an elementary physics course, threatens to quit. His reason is that he learned that Newton’s Third Law says that every force has an equal and opposite force. Thus, however strongly the locomotive pulls on the rest of the train, the train pulls back just as strongly on the locomotive so the train can’t possibly move. How do you convince him to go back to work?

You throw a ball straight upward. At the instant it stops at the top of its path, the velocity of the ball is




You throw a ball straight upward. At the instant it stops at the top of its path, the acceleration of the ball is

A. directed opposite to the velocity. B. zero. C. in the downward direction. D. in the upward direction. E. in the horizontal direction.

I have a mass of 70 kg. How much do I weigh? a) 700 kg. b) 700 nt c) 700 lbs d) 7 nt. e) 70 kg.

I have a mass of 60 kg. What is my mass on the Moon where the acceleration due to gravity is 1/6th of that on Earth?

a) 60 kg b) 60 nt c) 6 kg d) 6 nt e) You can’t tell from the information given.

Joe weighs 180 lbs. How much does he weigh on the Moon where the acceleration due to gravity is 1/6th of that on Earth?

a) 180 lbs. b) 30 lbs c) 180 x 6 = 1080 lbs d) 30 kg. e) You can’t tell from the information given.

A fly hits the windshield of a car that is traveling at 100 km/hr.

A. The force of the car on the fly is larger than the force of the fly on the car.

B. The force of the fly on the car is larger than the force of the car on the fly.

C. The force of the fly on the car is equal to the force of the car on the fly. D. The fly does not exert a force on the car because it is flying so slowly. E. The car doesn’t exert a force on the fly because the fly is so light.

Suppose you throw an apple horizontally. Neglecting air resistance, just after you release the apple from your hand, the net force on the apple is

A. zero. B. directed horizontally backward. C. directed horizontally forward. D. directed upward. E. directed downward.






A. directed opposite to the velocity. B. zero. C. in the downward direction. D. in the upward direction. E. in the horizontal direction.

You drop a ball straight downward. Just when you release it, the velocity of the ball is zero. At this instant, the net force on the ball is


A ripe apple falls from a tree. What force makes the apple fall? A. The gravitational pull from Earth. B. The tree pushes the apple down. C. Air pressure D. Inertia. E. Friction.

The Moon is in orbit around the Earth. What force keeps the Moon in its orbit? A. Not a force – just the Moon’s inertia. B. The centrifugal force. C. Gravity. D. The force that is equal and opposite to gravity. E. The electromagnetic force

What force balances the downward pull of gravity on a satellite while it is in orbit around Earth?

A. The centrifugal force B. The acceleration of the satellite C. The inertia of the satellite D. A balancing force is not needed because gravity doesn't act on the

satellite E. There is no balancing force--gravity is the only force on the satellite

An astronaut's normal weight is 600 newtons. How much will she weigh while in a rocket ship 60 km above the surface of Earth? (assume g = 10 m/s2)

A. zero – she’s weightless B. 67 newtons C. 150 newtons D. 300 newtons E. 600 newtons

An astronaut's normal weight is 600 newtons. How much will she weigh while in a rocket ship 6,000 kilometers [one earth radius] above the surface of Earth? (assume g = 10 m/s2)

A. zero – she’s weightless B. 67 newtons C. 150 newtons D. 300 newtons E. 600 newtons

Why does a person in an elevator that is in free-fall feel weightless? A. There are no forces acting on the person. B. The floor of the elevator doesn’t exert a normal force on the person

because they are both undergoing the same acceleration. C. The downward force of gravity is counterbalanced by the inertia of the

person. D. The person is too busy screaming to notice his weight. E. Since the gravitational force is still acting, the person cannot feel

weightless. You (a 150 lb person) are on a scale in an elevator that starts going upward. What does the scale read?

A. 150 lb. B. More than 150 lb. C. Less than 150 lb. D. Zero. E. Scales do not know how to read.

What keeps the Sun from contracting from gravity? A. It is contracting, but too slowly to notice. B. Outward radiation pressure. C. The outward flux of neutrinos. D. The Sun is solid – it can’t contract. E. Its rotation (centrifugal force).

According to current theories, how did the Sun's planets form? A. After the Sun had formed, it captured fully formed planets from

various places as the sun moved through the galaxy. B. Stars such as the Sun, and planets such as those around the Sun, all

formed shortly after the big bang, and then gathered into "solar systems" such as we see today.

C. Part of the gas and dust that gathered together to form the Sun went into orbit around the sun instead of falling into the Sun, and this matter coalesced into the planets.

D. A passing star tore off part of the Sun, and this part separated into pieces to form the planets.

E. The Sun was originally part of the two-star (binary) system. The second star split up into pieces, and these pieces developed into the planets.

Which of the following statements best describes the limitations of Newtonian physics? A. As far as we know, Newtonian physics is correct in all situations. B. At very high speeds, Newtonian physics gives very incorrect

predictions, and is correct in all other situations. C. At very high speeds, or at very small sizes, or for gases and liquids,

Newtonian physics gives very incorrect predictions. D. Newtonian physics is approximately correct, to within 1 or 2 percent,

in all situations. E. At high speeds, or at small sizes, or for large distances, Newtonian

physics is incorrect. You throw a ball straight upward. At the instant it stops at the top of its path, the velocity of the ball is





a) directed opposite to the velocity. b) zero. c) in the downward direction. d) in the upward direction. e) in the horizontal direction.



The moon’s orbit around the earth is nearly circular with a constant speed. Which of the following describes the moon’s motion:

A. Not accelerated. B. Accelerated with the acceleration along the direction of the moon’s

velocity. C. Accelerated with the acceleration opposite to the direction of the

moon’s velocity. D. Accelerated with the acceleration towards the center of the earth. E. Accelerated with the acceleration towards the sun.

As the moon is undergoing accelerated motion, what force is causing the acceleration? A. Gravity. B. The centrifugal force. C. The normal force. D. The abnormal force. E. The premise is incorrect. There is no force involved.

Why does a person in an elevator that is in free-fall feel weightless? A. There are no forces acting on the person. B. The floor of the elevator doesn’t exert a normal force on the person

because they are both undergoing the same acceleration. C. The downward force of gravity is counterbalanced by the inertia of the

person. D. The person is too busy screaming to notice his weight. E. Since the gravitational force is still acting, the person cannot feel

weightless. You (a 150 lb person) are on a scale in an elevator that starts going upward. What does the scale read?

a) 150 lb. b) More than 150 lb. c) Less than 150 lb. d) Zero. e) Scales do not know how to read.

What keeps the Sun from contracting from gravity? a) It is contracting, but too slowly to notice. b) Outward radiation pressure. c) The outward flux of neutrinos. d) The Sun is solid – it can’t contract. e) Its rotation (centrifugal force).

During a lecture, I (often) whirled a ball on a string over my head in a horizontal circle. The figure below illustrates the path of the ball and the string as viewed from above. If the string broke when the ball reached point A (traveling counterclockwise), which of the curves sketched on the figure most accurately illustrates the ensuing path of the ball? Explain your answer in terms of the physics we have studied.

According to current theories, how did the Sun's planets form?

a) After the Sun had formed, it captured fully formed planets from various places as the sun moved through the galaxy.

b) Stars such as the Sun, and planets such as those around the Sun, all formed shortly after the big bang, and then gathered into "solar systems" such as we see today.

c) Part of the gas and dust that gathered together to form the Sun went into orbit around the sun instead of falling into the Sun, and this matter coalesced into the planets.

d) A passing star tore off part of the Sun, and this part separated into pieces to form the planets.

e) The Sun was originally part of the two-star (binary) system. The second star split up into pieces, and these pieces developed into the planets.

Which of the following statements best describes the limitations of Newtonian physics? a) As far as we know, Newtonian physics is correct in all situations. b) At very high speeds, Newtonian physics gives very incorrect predictions,

and is correct in all other situations. c) At very high speeds, or at very small sizes, or for gases and liquids,

Newtonian physics gives very incorrect predictions. d) Newtonian physics is approximately correct, to within 1 or 2 percent, in all

situations. e) At high speeds, or at small sizes, or for large distances, Newtonian physics

is incorrect.






a) directed opposite to the velocity. b) zero. c) in the downward direction. d) in the upward direction. e) in the horizontal direction.



When a gas contracts, it: a) Cools. b) Gets hotter. c) Stays the same temperature.

Which of the following statements best describes the limitations of Newtonian physics?

a) As far as we know, Newtonian physics is correct in all situations. b) At very high speeds, Newtonian physics gives very incorrect

predictions, and is correct in all other situations. c) At very high speeds, or at very small sizes, or for gases and liquids,

Newtonian physics gives very incorrect predictions. d) Newtonian physics is approximately correct, to within 1 or 2 percent,

in all situations. e) At high speeds, or at small sizes, or for large distances, Newtonian

physics is incorrect.

Express 260,000 in scientific notation: a) 2.6 × 10-5 b) 2.6 × 105 c) 2.6 × 106 d) 260,000 e) 2.6 × 103

Why do you feel a gravitational pull from the Earth but not from the person sitting next to you?

a) You do perceive the gravitational force due to the person sitting next to you but it is canceled by the force due to the person on your other side.

b) The gravitational force only applies to (large) astronomical objects. c) Because of Newton’s 3rd Law. d) The relatively small mass of the person leads to an extremely tiny

gravitational force. e) You are closer to the person next to you so the gravitational force is

smaller. About how large is a hydrogen atom?

a) 10-15 meters b) 10-10 meters c) 10-8 meters d) 1 micron e) It is too small to measure.

If the Sun were somehow to cool somewhat, it would expand in size but its mass would not change. How does this affect the gravitational force exerted by the Sun on the Earth?

a) It increases. b) It stays the same. c) It decreases. d) It depends on the final radius of the Sun. e) You can’t tell from the information given.

You step on the accelerator of your car. What force causes the car to move forward? a) Friction. b) The turning of the car’s wheels. c) The normal force. d) The force from the engine. e) You can’t tell from the information given.

Nearly everybody agrees that the Earth is presently getting warmer. There is disagreement as to why this occurring. While there may be several reasons for this, which of the following do you believe is the major reason for global warming?

a) The Earth is getting closer to the Sun. b) The Sun is getting hotter. c) Greenhouse gases in the atmosphere. d) The ozone hole. e) It is part of the natural cyce of global climate changes

One situation in which the law of conservation of energy is violated is a. for atomic-sized objects. b. for very fast-moving objects. c. near black holes. d. all of the above. e. nonsense--no violations of this law have ever been observed.

A meteor having a mass of 1000 kg moves through outer space, far from all planets and stars and far from all gravitational influences, at a speed of 20 km/s (20,000 m/s). How much work is done on the meteor while it moves 20,000 m?

a. 1000 J. b. 20,000 J. c. 20 ×106 J. d. 20 J. e. None of the above.

You put a book on a shelf 2 meters above the floor. Relative to its position on the floor, the book has:

a. Kinetic energy. b. Gravitational potential energy. c. Thermal energy. d. Electromagnetic energy. e. Power.

The book falls and hits the floor. Just before hitting the floor, the book has: a. Kinetic energy. b. Gravitational potential energy. c. Thermal energy. d. Electromagnetic energy. e. Power.

After the book hits the floor it stops. The kinetic energy the book had has been converted into:

a. Thermal energy. b. Gravitational potential energy. c. Sound. d. Electromagnetic energy. e. The energy is lost.

Energy could best be defined as a. the ability to do work. b. matter in motion. c. the amount of force a system is capable of exerting. d. stored momentum. e. the ability to exert power.

The type of energy represented by the water behind a dam is a. kinetic. b. chemical. c. thermal. d. electromagnetic. e. gravitational.

Which of the following is an example of chemical energy? a. the energy stored in firewood that has been gathered for burning b. the energy stored in your body fat, that enables you to do work c. both of the above d. the energy in a stretched rubber band e. the energy in hot steam

A gas can containing a gallon of gasoline is stored in a basement. This gasoline contains:

a. work. b. energy. c. both work and energy. d. neither work nor energy. e. both energy and power.

Under what condition can a force act on an object and yet do no work on that object? A. If the object moves with no acceleration. B. If the object does not move. C. If the net force on the object decreases to zero. D. If the force operates at constant (unchanging) power. E. Nonsense-‐-‐any force on an object must do work on that object.

James Prescott Joule's experiments, such as stirring a container full of liquid, showed that

a. energy is conserved when all forms are included. b. the "Newtonian" energy forms [kinetic, gravitational, elastic] are

conserved. c. thermal energy is actually a form of energy. d. radiant energy is actually a form of energy. e. Mr. Joule did not know how to make a good batch of chili.

A low-‐power source of energy could put out a lot of work provided it a. operated for a long time. b. operated for a short time. c. exerted a sufficiently strong force. d. exerted its power over a very large distance. e. nonsense-‐-‐ there is no way that a low-‐power source can put out a

large amount of work. An electric light bulb converts one kind of energy to another. What kinds of energy are involved?

a) Potential energy into kinetic energy. b) Electrical energy into radiant energy. c) Electrical energy into heat. d) Mechanical energy into electrical energy. e) Both B and C.

What is the difference between heat and temperature? a) Temperature is how hot something is while heat is how much heat

something has. b) Temperature is the average amount of heat each molecule has. c) Temperature measures hot and cold, heat measures energy. d) Temperature is actually a form of energy. e) There is no difference.

Comparing two motors with different power rating, the higher-‐power motor must: a. exert a larger force than the lower power motor. b. exert a larger torque than the lower power motor. c. do more work than the lower power motor. d. operate more efficiently than the lower power motor. e. none of the above.

A low-‐power source of energy could put out a lot of work provided it a. operated for a long time. b. operated quickly. c. exerted a sufficiently strong force. d. exerted its power over a very large distance. e. nonsense-‐-‐ there is no way that a low-‐power source can put out a large

amount of work. Conventional automobile efficiencies cannot conceivably be higher than about 25%, even with perfect engineering. This is due to

A. road friction. B. air resistance plus road friction. C. frictional loses inside the car plus unburned hydrocarbons. D. the law of conservation of energy. E. the second law of thermodynamics.

When a cold gas comes in contact with a hot gas, we say that heat flows from the hot to the cold. What physical process is responsible for this heat flow?

a) the hot molecules and the cold molecules mix. b) faster moving molecules tend to lose energy when they collide with slower

moving molecules. c) faster moving molecules always lose energy when they collide with slower

moving molecules. d) heat is a fluid that flows from the hot to the cold molecules. e) the premise of this question is wrong – coolth flows from the cold molecules

to the hot molecules. What is the probability of flipping a coin 6 times and getting all heads compared with getting heads, tails, heads, heads, tails, tails (in exactly that order)?

A. 6 heads is much less probable. B. 6 heads is a little less probable. C. they are equally probable. D. 6 heads is more probable. E. I thought this was a physics course, not a course on gambling.

Which of the following is not a possible energy source for a steam-‐electric generating plant?

A. fossil fuels B. fissionable material such as uranium C. wood D. solar energy E. all of the above are possible energy sources

Does the growth of a leaf violate the 2nd law of thermodynamics, and why or why not?

A. No, because the energy increase of the leaf is exactly balanced by the energy decrease of the radiation flowing through the leaf.

B. No, because the increase in the entropy of the radiation passing through the leaf is greater than the decrease in the entropy of the leaf itself.

C. No, because the leaf actually increases its own entropy in this process, despite the appearance that it is becoming better organized.

D. Yes, because this law is violated in situations involving energy from the sun.

E. Yes, because this law is violated by living organisms. Which laws of physics, if any, distinguish between the backward and the forward direction in time?

a. None. b. The law of conservation of energy and the second law of thermodynamics. c. The law of conservation of energy but not the second law of

thermodynamics. d. The second law of thermodynamics but not the law of conservation of

energy. e. Newton's laws of motion.

The freezing point of water at sea level is: a) 0° K. b) 0° C. c) 0° F. d) 32° K. e) 273° F.

The temperature in this room right now is about: a) 0° C. b) 10° C. c) 20° C. d) 45° C. e) 70° C.

In which case is the 2nd temperature twice as hot as the second? a) 10° C and 20° C b) 10° F and 20° F. c) 10 K and 20 K. d) All of the above. e) None of the above.

At what temperature does water boil at sea level? A. 0° C. B. 100° C C. 100° F. D. 100 K. E. 373 K.

The first law of thermodynamics states: a) Energy is the capacity to do work. b) Doing work means exerting a force through a distance. c) Heat flows from a hot body to a cooler body. d) Energy is neither created nor destroyed. e) Mechanical energy is always conserved.

The kelvin temperature of an object is a measure of a. the total energy of the molecules of the object. b. the total kinetic energy of the molecules of the object. c. the maximum energy of the molecules of the object. d. the average kinetic energy of the molecules of the object. e. The amount of heat contained in an object.

A large iron ball at 10°C and a smaller iron ball at 50°C are dropped into a large vat of water that is at 30°C. After a long while, which situation is reached?

a) The larger ball will be cooler than the smaller ball. b) The smaller ball will be cooler than the larger ball. c) Both balls will reach the same temperature but the water will remain

at 30°C. d) Both balls and the water will reach the same temperature. e) Who cares? (hint: this may be true but getting credit for this is highly

unlikely) Which of the following is not a possible energy source for a steam-‐electric

generating plant? a) fossil fuels b) fissionable material such as uranium c) wood d) solar energy e) all of the above are possible energy sources

Does the growth of a leaf violate the 2nd law of thermodynamics, and why? 1. No, because the energy increase of the leaf is exactly balanced by the

energy decrease of the radiation flowing through the leaf. 2. No, because the increase in the entropy of the radiation passing

through the leaf is greater than the decrease in the entropy of the leaf itself.

3. No, because the leaf actually increases its own entropy in this process, despite the appearance that it is becoming better organized.

4. Yes, because this law is violated in situations involving energy from the sun.

5. Yes, because this law is violated by living organisms.

Which laws of physics, if any, distinguish between the backward and the forward direction in time?

a) None. b) The law of conservation of energy and the second law of

thermodynamics. c) The law of conservation of energy but not the second law of

thermodynamics. d) The second law of thermodynamics but not the law of conservation of

energy. e) Newton's laws of motion.

How is Coulomb’s Law (the law describing the electrostatic force) similar to the gravitational force? a) They both involve action at a distance. b) They both vary as 1/r2, where r is the distance between the two

charges and masses, respectively. c) They are always attractive. d) All of the above. e) A and B above.

J. J. Thomson did an experiment using cathode rays, thus demonstrating: a) The existence of the electric field. b) The existence of the magnetic field. c) The existence of the negatively charged electron. d) The existence of the positively charged proton. e) The plum pudding model of the atom.

A mouthful of water contains ~1024 electrons. Why isn’t it strongly attracted to you, who contain ~1027 protons?

a. Protons and electrons have the same charge. b. Opposite charges repel. c. The electrostatic force doesn’t apply to living bodies. d. Neither the water nor you are charged – each contain equal numbers

of electrons and protons. e. The electric force is balanced by the gravitational force.

How do we know that the charge on an electron is, to extremely high accuracy, equal and opposite to the charge on a proton? a. The charge on each has been measured and they are consistent with

being equal and opposite. b. The Law of Conservation of Charge. c. The fact that ordinary matter, which contains huge numbers of

electrons and protons, is generally electrically neutral. d. The 2nd Law of Thermodynamics. e. Actually, we don’t know this very well.

What are the major differences between protons and electrons? a. Protons are ~2000 more massive than electrons. b. Electrons are ~2000 more massive than protons. c. They have equal but opposite electric charges. d. a) and c) above. e. b) and c) above.

True or false – electric charge can only take on certain discrete values (i. e. it is quantized) ?

a. True. b. False. c. It depends on whether you are talking about free charges or charges

in metals. d. It depends on whether you are talking about free charges or charges

in semiconductors. e. It is quantized on Earth but not necessarily elsewhere in the Universe.

The electric field in the region around a charge of +0.5 Coulomb a. Points towards the charge. b. Points away from the charge. c. Increases as you get farther away from the charge. d. Is constant. e. Cannot exist in a vacuum.

Consider two objects, A and B. Object A is uncharged and object B has a net charge +q. Based on this information, what can you tell about whether these bodies are conductors or insulators?

a. Object A must be conductor. b. Object B must be a conductor. c. Object B must be an insulator. d. Both objects must be insulators. e. You can’t tell whether either is a conductor or an insulator.

The average velocity of electrons in the wire connected to a shining light bulb is: a) about 1000 feet/s. b) 3 ×108 m/s. c) Infinite. d) About 1 m/s. e) About 0.1 m/hr.

Ohm’s Law is: a) A fundamental law of physics. b) Always obeyed. c) Obeyed by some materials but not by others. d) Both a) and b). e) A blatant but successful attempt by Georg Simon Ohm to become

famous. The magnetic pole located in Northern Canada is:

a) A north magnetic pole. b) A south magnetic pole. c) Caused by a huge bar magnet deep underground. d) Neither magnetic nor a pole. e) Above ground.

A moving electron produces: a) Only an electric field. b) Only a magnetic field. c) An electric and a magnetic field. d) Neither an electric or a magnetic field. e) An ion.

Electric power generation is based on: a) A DC Motor. b) The movement of protons in a conductor. c) The movement of a wire loop in an electric field. d) The movement of a wire loop in a magnetic field. e) The conversion of electrical energy to mechanical energy.

As the wavelength of a light wave increases, its frequency: a) Increases. b) Is unchanged. c) Decreases. d) Can either increase or decrease.

The frequency of a wave is a) How fast the wave travels. b) The number of oscillations per second at a fixed spatial position. c) The height of the oscillation. d) The distance between successive oscillations. e) How often a phenomenon produces a wave.

Light waves are a. traveling disturbances of air molecules. b. traveling disturbances of an electromagnetic field. c. traveling disturbances in the ether. d. beams of moving electrons and other charged particles. e. beams of moving atoms

An electromagnetic wave consists of: a) Electrons oscillating perpendicular to the direction of motion b) Electrons oscillating parallel to the direction of motion. c) Oscillating parallel electric and magnetic fields that are each perpendicular to

the direction of motion. d) Oscillating parallel electric and magnetic fields that are each parallel to the

direction of motion. e) Oscillating electric and magnetic fields that are each perpendicular to each other

and to the direction of motion. The three main types of radiation produced by the sun are

a. alpha, beta, and gamma. b. gamma, visible, and ultra-‐violet. c. radio, infra-‐red, and visible. d. visible, radio, and gamma. e. infra-‐red, visible, and ultra-‐violet.

A typical source of infrared radiation is a) electrons moving along a metal antenna. b) magnetized particles vibrating in iron and certain other metals. c) electrons orbiting the nucleus in atoms. d) charged particles moving within the nucleus. e) thermal vibrations of molecules.

Your radio is tuned to 98 on the FM dial. What electromagnetic wave frequency is your radio receiving, and how fast is this wave traveling?

a. 98 x 106 Hz, at the speed of sound. b. 98 x 106 Hz, at a speed of 300,000 km/s. c. 98,000 Hz, at the speed of sound. d. 98,000 Hz, at a speed of 300,000 km/s. e. 98 Hz, at a speed of 300,000 km/s.

Is it possible for scientists to determine the CO2 content of the atmosphere in pre-‐historic times?

a) No, because nobody was making atmospheric measurements at that time. b) No, because CO2 is a gas and so it is not preserved in the fossil record. c) Yes, by using computers and calculating backward in time starting from

today's atmosphere. d) Yes, by measuring the CO2 content in the depths of the ocean. e) Yes, by measuring the CO2 content in deep ice cores.

A greenhouse in the sun warms up because: a) Energy is not conserved. b) The sunlight enters the greenhouse and no energy leaves. c) The glass lets the sunlight in but doesn’t let much longer wavelength

radiation out. d) Glass is clear so it doesn’t transmit black body radiation. e) The glass only lets light in, not out.

A train is moving eastward past a man on the platform at 70 m/s. She throws a ball forward at 20 m/s. What velocity of the ball does the man observe?

a) 90 m/s eastward b) 70 m/s westward c) 50 m/s eastward d) 50 m/s westward e) 70 m/s eastward

According to the principle of relativity, an observer who has no communication with the world outside of her laboratory (an inertial frame of reference) will be unable to detect

a) her laboratory's acceleration. b) her laboratory's velocity. c) both of the above. d) gravity. e) all of the above.

A woman is in a rocket ship moving north past a man at half of lightspeed (c) relative to him. She fires a laser beam forward from the front of her ship. He sees the laser beam move at

a) slightly slower than speed c. b) c. c) 0.5c. d) 1.5c. e) slightly faster than c.

Einstein believed that the principle of relativity should apply to Maxwell's theory of electromagnetism. Which basic principle or law did this lead Einstein to propose?

a) the relativity of time b) E = mc2 c) the law of inertia d) the constancy of the speed of light for all observers e) length contraction

A greenhouse in the sun warms up because: a) The glass only lets light in, not out. b) Energy is produced inside the greenhouse. c) The sunlight enters the greenhouse and no energy leaves. d) The glass transmits visible and UV radiation but not IR radiation. e) Glass is clear so it doesn’t transmit black body radiation.

According to the principle of relativity, an observer who has no communication with the world outside of her laboratory (an inertial frame of reference) will be unable to detect

a. her laboratory's acceleration. b. her laboratory's velocity. c. both of the above. d. gravity. e. all of the above.

To what form or forms of energy does the relationship E = mc2 apply? a) Kinetic energy only b) Thermal energy only c) Nuclear energy only d) Only kinetic energy and nuclear energy e) All forms of energy

A woman is in a rocket ship moving north past a man at half of lightspeed (c) relative to him. She fires a laser beam forward from the front of her ship. He sees the laser beam move at

a) slightly slower than speed c. b) c. c) 0.5c. d) 1.5c. e) slightly faster than c.

What is the source of the Sun’s energy? a) Gravitational collapse b) Combustion of hydrogen c) Nuclear fusion d) Nuclear fission e) An electric generator caused by the rotating solar magnetic field

The relativity principle applies to: a) Inertial reference frames only b) Accelerating reference frames only c) All reference frames d) Only to objects moving at relativistic speeds e) Only to objects moving at nonrelativistic speeds

You are riding on an electron that is accelerated to 0.99c. According to your measurements, how much has the mass of the electron increased?

a) Not at all. b) By a negligible amount. c) By a factor of about 1.5 d) By a factor of about 7. e) The mass of the electron has decreased.

According to the principle of equivalence, gravity is equivalent to a) velocity. b) the state of free-‐fall. c) acceleration. d) net force. e) energy.

In coming to the conclusion that light beams are bent by gravity, Einstein reasoned that

a) since all observers experience the same laws of physics, Newton's theory of gravity must apply to light beams.

b) since light speed is the same for all observers, moving observers would observe that light beams bend.

c) fast-‐moving observers would find that light beams bend, so gravity must also bend light beams.

d) accelerated observers would find that light beams bend, so gravity must also bend light beams.

e) increased mass at higher velocities causes increased gravitational effects, so light beams moving at light speed should have gravitational effects.

Gravitational lensing is possible because : a. Light bends in a gravitational field. b. Gravitational waves move slower than c in some situations. c. The velocity of light is always the same for all observers. d. Nonsense, there is no such thing as gravitational lensing. e. The Big Bang.

How can one detect a black hole? a) By its gravitational effects on other bodies. b) By seeing a black region in the sky. c) By observing light emerging from them. d) By detecting the gravitational waves they produce. e) By listening for the sucking sound.

What is a black hole? a) An object that emits a black body spectrum. b) An object that absorbs black body radiation. c) An object that is so dense that the escape velocity is greater than the

velocity of light. d) The only kind of object that bends light. e) Your mind when you think about physics.

How can one detect a black hole? a) By its gravitational effects on other bodies. b) By seeing a black region in the sky. c) By observing light emerging from them. d) By detecting the gravitational waves they produce. e) By listening for the sucking sound.

When bright light of a single frequency passes through two very small very closely-‐spaced vertical slits, what is observed?

a) Shadows of the two slits. b) The light spreads out and uniformly hits the screen. c) A pattern of alternating bright and dark vertical stripes. d) No light hits the screen due to destructive interference. e) Light of a different wavelength due to the Doppler effect.

The double-‐slit experiment conducted with bright light of a single frequency demonstrates:

a) Diffraction. b) Interference. c) Refraction d) That light is a wave. e) That light energy is quantized.

The double-‐slit experiment conducted with very faint light of a single frequency also demonstrates:

a) Diffraction. b) Interference. c) Refraction d) That light is a wave. e) That light energy is quantized.

What is a photon? a) The antiparticle of an electron. b) A quantum of electromagnetic energy. c) The nucleus of a hydrogen atom. d) A charged subatomic particle. e) Another name for a neutrino.

Energy in electromagnetic radiation is quantized. The energy of the quantum is: a) E = h f ( f = frequency) b) E = h λ (λ = wavelength) c) E = m c2 d) E = h / (m v) e) E = ½ m v2

Why didn’t Newton realize that electromagnetic energy was quantized? a) Electromagnetic energy wasn’t invented yet. b) Newton only cared about mechanics. c) The quantum of electromagnetic energy is too small to have been

observable with the instruments Newton had. d) Newton was too busy with alchemy. e) He did – he just didn’t publish this result.

The realization that an atom consisted of a small, heavy nucleus with electrons orbiting around it came from:

a. An experiment in which alpha particles scattered from a gold foil. b. An experiment comparing the velocity of light along the direction of

the Earth’s motion with light traveling perpendicular to this direction.

c. A careful study of black body radiation. d. Einstein’s explanation of Brownian motion. e. The realization that relativistic particles can behave like waves.

According to the uncertainty principle: a. any measurement may be in error. b. the precision with which one can know the position of a particle is

limited. c. the precision with which one can know the velocity of a particle is

limited. d. the product of the precision with which one can know the position

and the velocity of a particle is limited. e. There are always things about physics that students don’t

understand. What happens to an electron's wave packet if an accurate velocity measurement is performed?

a) It suddenly changes to a new wave packet having a very small uncertainty in velocity, but a large uncertainty in position.

b) It suddenly changes to a new wave packet having small uncertainties in both velocity and position.

c) It suddenly changes to a new wave packet having a very small uncertainty in position, but a large uncertainty in velocity.

d) The wave packet is unaffected by the measurement, even though the electron itself makes a sudden change of state that is caused by the measurement.

e) Neither the wave packet nor the electron is affected by the measurement.

What is the emission spectrum from a glowing tube of Oxygen? a) A black body spectrum b) A continuous spectrum like sunlight c) A series of emission lines at discrete wavelengths d) A continuous spectrum with a series of dark lines. e) A single color.

The difference between a black body spectrum and a line emission spectrum is: a) Black bodies emit a black body spectrum while a line spectrum is

emitted by an element. b) A black body spectrum is continuous while a line spectrum consists

of a number of discrete wavelengths. c) A black body spectrum is black while a line spectrum consists of

colors. d) A black body spectrum is emitted by a gas while a line spectrum is

emitted by a hot solid object. e) There is no difference between them.

Of the four fundamental forces that act in the universe, which one supports a book that is at rest on a table?

a) the strong nuclear force b) the electromagnetic force c) the perpendicular force d) the gravitational force e) the photon force

How many protons and how many neutrons are in the 2656Fe nucleus? a) 26 protons and 30 neutrons b) 26 protons and 56 neutrons c) 30 protons and 26 neutrons d) 56 protons and 26 neutrons e) none of the above

How do the mass and charge of a 14C nucleus compare with the mass and charge of a 12C nucleus?

a) The mass of 14C is 50% larger, while the charge is the same. b) Both the mass and the charge of 14C are the same as those of 12C. c) Both the mass and charge of 14C are one-‐sixth larger. d) The mass is the same, while the charge of 14C is one-‐sixth larger. e) The mass of 14C is one-‐sixth larger, while the charge is the same.

Radioactive decay occurs when a) a nucleus is struck and broken into pieces by a fast moving particle. b) bacteria and other microscopic organisms digest nuclear particles. c) an atom loses one or more orbital electrons. d) two or more nuclei fuse together. e) a nucleus emits a particle spontaneously

The force that holds the nucleus together a) acts over only very short distances. b) is much stronger than electromagnetic forces. c) both of the above. d) is attractive, that is, it pulls in the inward direction. e) all of the above

Radon has a 4-‐day half-‐life. Starting with 10 radon atoms, how many will remain after 4 days?

a) About 5, but this prediction is uncertain due to quantum uncertainties.

b) About 5, but this prediction is uncertain due to the inaccuracies of our measuring devices.

c) Precisely five. d) Precisely zero. e) Either four, or five, or six.

How old is Earth, according to the vast majority of scientists? a) a few thousand years b) a few million years c) about a billion years d) a few billion years e) about 100 billion years

In the Bohr model of the atom: a) Electrons and protons are sprinkled throughout a region 10-‐10 m in

diameter. b) Electrons orbiting the nucleus radiate energy continuously. c) Electrons in the ground state do not radiate. d) Electrons radiate only when they drop from an excited state to a

lower energy state. e) Electron energy levels are quantized.

Chemistry depends upon the behavior of: a) The protons in the nucleus. b) The neutrons in the nucleus. c) The strong nuclear force. d) The atomic electrons. e) The gravitational attraction between atomic electrons and the

nucleus. In a periodic table, the elements are arranged in order of ascending atomic number and show:

a) That some elements are heavier than others. b) That there are many different elements. c) Atomic spectra of neighboring elements are similar. d) The names of the elements are alphabetical. e) Families of elements with similar chemical properties.

The force that holds the nucleus together a) acts over only very short distances. b) is much stronger than electromagnetic forces. c) both of the above. d) is attractive, that is, it pulls in the inward direction. e) all of the above

The largest source of our natural exposure to radioactivity comes from: a) radioactive fallout from weapons tests. b) radon c) cosmic rays d) nuclear power plants e) medical procedures (X-‐rays, MRI, etc.)

Our present view of the structure of matter is: a) the plum pudding model – protons, neutrons and electrons

uniformly spread over a region ~10-‐10 m. b) a planetary model with a small (~10-‐15 m) nucleus held together by

gravity with electrons orbiting around it. c) a planetary model with a small (~10-‐15 m) nucleus held together by

the strong force with electrons orbiting around it. d) a planetary model with a small (~10-‐15 m) nucleus held together by

the weak force with electrons orbiting around it. e) a planetary model with a small (~10-‐15 m) nucleus held together by

the electromagnetic force with electrons orbiting around it.

If you constructed a helium nucleus from 2 free protons and 2 free neutrons: a) You would have to supply a lot of energy as the protons repel each

other. b) There would be a net release of energy. c) The resulting nucleus would be unstable. d) There would be a small release of energy because the weak nuclear

force is weak. e) You would produce a nuclear explosion.

Except for hydrogen, helium, and a little lithium, the lower-‐mass elements (lighter than iron) that are spread throughout the dust of the universe were created

a) in the original creation of the universe. b) during the fusion process that powers the stars, and then released in

supernova explosions. c) in the shock wave of a supernova explosion. d) in hot white dwarf stars. e) in Kansas.

Hydrogen must be raised to a high temperature before it will fuse in the Sun. This is because

a) this reaction consumes more thermal energy than it produces. b) high temperatures are needed to overcome the electric repulsion

between hydrogen nuclei. c) fusion and all other forms of chemical combustion must be initiated

by high temperatures. d) high temperatures are needed to overcome the strong nuclear force

between hydrogen nuclei. e) this reaction must consume a large amount of thermal energy in

order to produce nuclear energy. In a fission reaction, such as occurs in a nuclear power plant,

a) energy is created. b) nuclear energy is created. c) thermal energy and other forms of energy are converted to nuclear

energy. d) heat is converted to work. e) nuclear energy is converted to thermal energy and other forms of

energy. In order for a substance to sustain a fission chain reaction, one important condition is that

a) each fissioning nucleus must release a sufficient number of alpha-‐particles.

b) each fissioning nucleus must release a sufficient number of neutrons. c) energy must be continually supplied from the outside. d) the nuclei must collide with enough energy to overcome the

electrical repulsion between them. e) the nuclei must be electrically neutral.

A direct way to measure the distance to an astronomical object is: a) Using parallax. b) Measuring the time it takes light to travel from the object to us. c) Measuring the time it takes light to travel from us to the object. d) Measuring the time it takes to bounce light from the object. e) Measuring the apparent size of the object.

Edwin Hubble observed that all distant galaxies are moving away from us, and that the farther away they are, the faster they are receding. This is due to the fact that:

a) Every other galaxy hates us. b) We are at the center of the expanding universe. c) The speed of light is always c. d) The universe is expanding as a result of the Big Bang. e) Einstein’s Theory of General Relativity says that space is curved.

Today, the energy resource that supplies the U.S. with the greatest amount of electricity is

a) nuclear. b) coal. c) natural gas. d) oil. e) hydroelectric.

Which two renewable energy resources provide the largest amount of energy today?

a. photovoltaics and wind b. hydroelectric and wind c. biomass and active solar d. active solar and photovoltaics e. hydroelectric and biomass

A light-‐year is: a) The length of time it takes the Earth to go around the Sun. b) The length of time it takes the Earth to go around the Galactic center. c) The diameter of the Earth’s orbit around the Sun as measured by

light. d) The distance light travels in a year. e) Approximately 9× 1012 km.

The hydrogen spectral lines from a distant galaxy appear to be shifted to longer wavelengths (towards the red). This shows that:

a) the galaxy is moving rapidly away from us. b) the galaxy is moving rapidly towards us. c) Spectra are not the same everywhere in the universe. d) Something must be wrong with the measurement as all helium

spectra should be the same. e) Who cares?

Penzias & Wilson observed noise in their microwave antenna everywhere they looked in the sky. This was due to:

a) Pigeon poop. b) Poor experimental technique. c) Noisy electronics. d) Heat left over from the Big Bang. e) Supernova explosions.

Modern astronomical observations show that most of the matter in the universe is: a) Hydrogen and Helium. b) Iron. c) Not ordinary matter. d) Neutrinos. e) Luminous.

Iron is the most tightly bound nucleus. Where were the elements heavier than iron produced?

a) In the Big Bang. b) In the cores of stars. c) In Black Holes. d) In Supernovae. e) On Earth.

The horn of a car moving rapidly away from us has a lower pitch due to: a) Relativity. b) The Doppler effect. c) Diffraction of the sound waves. d) Refraction of the sound waves. e) This is not true – the pitch sounds normal.

Observations of a spectral line of helium from distant galaxies are shifted to longer wavelengths. This is because:

a) the galaxies are moving rapidly away from us. b) the galaxies are moving rapidly towards us. c) Spectra are not the same everywhere in the universe. d) Something must be wrong with the measurement as all helium

spectra should be the same. e) Who cares?

Edwin Hubble concluded that the universe is expanding by observing: a) a red shift in the light spectrum from distant galaxies. That is

proportional to their distance. b) a blue shift in the light spectrum from distant galaxies. That is

proportional to their distance. c) the distant galaxies getting smaller. d) an increase in the measured distance to the galaxies. e) Hubble didn’t do this.

If every dimension in the universe were doubled, the result would be: a) The Earth would be colder. b) The Earth would be warmer. c) We would be able to see farther. d) There would be no discernable effect. e) It is already happening due to the expansion of the universe.

Penzias & Wilson observed noise in their microwave antenna everywhere they looked in the sky. This was due to:

a) Pigeon poop. b) Poor experimental technique. c) Noisy electronics. d) Heat left over from the Big Bang. e) Supernova explosions.

Modern astronomical observations show that most of the matter in the universe is: a) Hydrogen and Helium. b) Iron. c) Not ordinary matter. d) Neutrinos. e) Luminous.

Recent astronomical observations show that the expansion of the universe is: a) accelerating. b) decelerating. c) constant. d) incorrect. e) violates the conservation of energy .

Iron is the most tightly bound nucleus. Where were the elements heavier than iron produced?

a) In the Big Bang. b) In the cores of stars. c) In Black Holes. d) In Supernovae. e) On Earth.

Today, the energy resource that supplies the U.S. with the greatest amount of electricity is

a) nuclear. b) coal. c) natural gas. d) oil. e) hydroelectric.

Which two renewable energy resources provide the largest amount of energy today?

a) photovoltaics and wind b) hydroelectric and wind c) biomass and active solar d) active solar and photovoltaics e) hydroelectric and biomass

physics102’ iclicker’questions’ - physics and...

Documents