motion and light 2010-2011. jag mark 1/3/11 genetics problems from science spot
TRANSCRIPT
Motion and Light
2010-2011
Jag Mark 1/3/11
Genetics problems from science spot.
Jag Mark 1/4/11
Name the Ologist set 1.
Jag Mark 1/5/11
Name the Ologist set 3.
Jag Mark 1/6/11
Name the Ologist set 4.
Jag Mark 1/7/11
Name the Ologist set 5.
Jag Mark 1/11/11 Sandra conducted a
velocity lab in science class. She races a hot wheel car from a starting point on an inclined plane. Her data can be found in the table. Use her data to determine the average speed of the car. Graph her results.
Point Distance Time
A 0.5m .33sec
B 1.0m .64sec
C 1.5m .92sec
D 2.0m 1.2sec
E 2.5m 1.48sec
Jag Mark 1/12/11
Tami has been assigned a science project for the science fair. She will be conducting an experiment to determine which teacher gives out the most homework during a nine weeks. Define the controls, independent, and dependent variables for her experiment.
Jag Mark 1/13/11
Draw a sketch of a distance vs time graph of a cyclist riding a bicycle for 200 meters in 45 seconds, then stopping for water for 10 seconds, then riding her bicycle for 500 meters in 2.5 minutes.
Classwork
READ pages 86-107 in Green Textbook. Complete guided reading on pages 37-44. (Answers only! READ FIRST!!!)
Jag Mark 1/14/11
Describe the differences between the Lithosphere and the Asthenosphere.
Describe the different types of boundaries that exist between tectonic plates.
Jag Mark 1/18/11
Ruby and Max are enjoying a snow day! The are sledding down their favorite hill. If they start at the top of the hill at 0m/s and then accelerate to 40m/s after 4 seconds, what is their rate of acceleration?
Label an acceleration graph with the appropriate x and y-axis.
Jag Mark 1/19/11
We are rearranging the science lab. (NOT REALLY…so don’t move any desk!) One student pushes a desk towards the window with a force of 10 N. Mrs. Foles pushes the desk away from the window with a force of 15 N. Draw a force diagram illustrating the forces. What is the magnitude and direction of the net force acting on the desk?
Jag Mark 1/20/11
Describe Newton’s 3 Laws of Motion and give an example of each.
Jag Mark 1/21/11
What is friction? Name 2 ways friction can be reduced and
why you would want to decrease friction. Name 2 ways friction can be increased and
why you would want to increase friction.
Jag Mark 1/24/11
Draw and label an electromagnetic spectrum illustrating at least 3 electromagnetic waves besides visible light.
Jag Mark 1/25/11
Test Day!
Motion Motion is a change in position over time. Motion depends on a reference point which is
an object used for comparison with the object in motion. Stationary objects are good reference points.
Position is an object’s location in relation to a reference point.
Reporting Motion
Qualitative: Describing motion Fast or slow
Quantitative: measuring motion Speed = Distance
Time Speed = 120 miles
2 hours Speed = 60 miles/hour
Speed vs Velocity
Velocity is speed plus direction. Speed = 60 miles/hour Velocity = 60 miles/hour north
Distance is how far the object traveled. Time measures how long it took the object to
travel the distance.
SPEED
Speed is the distance that an object travels in a period of time.
d
t v
Units are meters and seconds However, sometimes km/hr is more sensible.
A cyclist travels 25 km in ½ an hour.
What is their speed - in kmhr-1
- in ms-1
= 25km/0.5hr = 50km/hr
= 25000m/1800s = 13m/s
DISTANCE/TIME GRAPHSA car takes 1.5 minutes to travel 500m down a busy road. It stops at lights for 30 seconds, then continues on for 1 minute as it goes another 1km.
Plot this on a distance/time graph.
Time (min)1 2 3
Distance
(km)
0.5
1
1.5
Using the distance/time graph:
1.What is the total distance traveled?
2. In what part of the trip is the car going the fastest?
3. What is the fastest speed?
= 1.5 km
= part 3
v = Δd / Δt
v = 1km/1min
v = 1000m/60s
v = 16m/s
Steepest section is fastest
Δd = 1km
Δt = 1min
In a distance/time graph the slope of the line = the speed of the object.
SPEED QUESTIONSWhat would these look like on a distance/time graph?
1. stopped
2. slow
3. fast
4. accelerating
Motion on Earth
Theory of Plate Tectonics states that Earth’s plates move slowly in various directions through convection energy transfer in the mantle. (some push away; some push together)
Tectonic plates are large pieces of the lithosphere that are in constant motion.
Some move cm each year; others just mm Distance=5cm/year x 1000 years=5000cm (50m)
Motion on Earth Lithosphere is the rocky outer shell of Earth that
includes the crust and upper mantle. (brittle and rigid) more solid Continental Crust: composed of sedimentary, igneous,
and metamorphic rocks and make up the continents Oceanic Crust: more dense, thinner mafic rock layer
that makes up ocean basins The asthenosphere lies just below the
lithosphere. It is much hotter with a low density and very ductile. (plastic and flowing) more liquid
Motion on Earth Plate Boundary: Region where two tectonic
plates meet Transform (fault) boundary: Plates slide side
by side.
Convergent boundary: Plates move towards each other.
Divergent boundary: Plates move away from each other.
Oceanic-Continental Convergent: Oceanic plate is more dense and subducts the continental plate creating an ocean trench and a chain of volcanoes.
Continental-Continental Convergent: The two plates collide creating a mountain range.
Oceanic-Oceanic Convergent: collide to create volcanoes and islands in between.
Oceanic-Oceanic Divergent: Forms mid-oceanic ridges leading to underwater volcanoes that give rise to volcanic islands.
Continental-Continental Divergent: Produce rift valleys eventually creating oceanic plates.
Motion on Earth
Acceleration
Acceleration is the rate of change in speed, direction, or both.
Riding your bike at 2 km/h, you slow down to 1 km/h, and then increase speed to 1.5 km/h. (Each time you are accelerating)
acceleration = velocity final - velocityinitial
time
ACCELERATIONAcceleration is the change in speed in an object in a period of time.
Δ v
a Δ t
Units ms2
It takes a cyclist 20 seconds to go from a standing start to 14m/s.
What is their acceleration?
What is 14m/s in km/hr?
a = Δv/Δt a = 14m/s / 20s a = 0.7ms2
= 14 × 60s × 60min 1000m
= 50.4km/hr
SPEED/TIME GRAPHSA runner travels at 4m/s for 10 seconds, then stops suddenly for 5 seconds, then accelerates for 5 seconds to get to 8m/s and continues for 10 seconds.
Plot this on a speed/time graph.
Time (sec)10 20 30
Speed
(m/s)
4
8Using the speed/time graph:
In what part of the trip is the runner going the fastest?
What is the acceleration in part 4?
= part 5
In a speed/time graph the slope of the line = the acceleration of the object.
a = Δv/Δt
a = 8m/s/5s
a = 1.6ms2
ACCELERATION QUESTIONSWhat would these look like on a speed/time graph?
1. stopped
2. slow
3. fast
4. accelerating
SPEED/TIME GRAPHS
Time (sec)10 20 30
Speed
(m/s)
4
8
What distance is covered in part 1?
What is the total distance covered?
d = v × t
d = 4m/s × 10s
d = 40 m
Part 1 = 40m
Part 2 = 0m
Part 3 = v × t × = 8m/s × 5s × = 20m
Part 4 = v × t = 8m/s × 10 s = 80m
Total = 40 + 20 + 80 =140m
Part 1
Part 2
Part 3
Part 4
In a speed/time graph the distance covered = the area under the graph.
FORCES
Forces are pushes or pulls (a combination is a twist).
Objects are stationary when forces are balanced
gravity is always acting but we don’t keep falling due to a support force
Forces can be measured using a Newton meter.
BALANCED FORCESAn unbalanced forces cause changes to objects motion (speed or direction), or shape.
If a force acts on a stationary object and causes motion, the object has gained kinetic (movement) energy.
Friction will stop the object moving.
Types of force:
Gravity
Electrostatic
Tension – the force in rope, etcMagnetism
Friction – the force that opposes motion
Support
Buoyancy – in the water
Lift – in the air (planes/birds)
FORCE PAIRS
Forces act in pairs (e.g. thrust and friction, gravity and support).
Force diagrams show the forces acting on an object and whether they are balanced or unbalanced.
Force pairs
What are the missing terms?
Buoyancy Drag Thrust Weight
Newton’s 1st Law of Motion
An object at rest will remain at rest unless acted on by an unbalanced force. An object in motion continues in motion with the same speed and in the same direction unless acted upon by an unbalanced force.
Newton’s 2nd Law of Motion
Acceleration is produced when a force acts on a mass. The greater the mass (of the object being accelerated) the greater the amount of force needed (to accelerate the object).
Newton’s 2nd Law of Motion
EX: Mike's car, which weighs 1,000 kg, is out of gas. Mike is trying to push the car to a gas station, and he makes the car accelerate at 0.05 m/s/s. Using Newton's Second Law, compute how much force Mike is applying to the car.
FORCE AND MOTIONWhat happens when you apply a small constant force to a trolley and time it over a set distance?
Small constant force
An unbalanced force causes acceleration.
The trolley should accelerate because…
Set distance
FORCE AND MOTIONWhat happens when you apply a small constant force to a trolley carrying a 1kg mass and time it over a set distance?
Small constant force
The larger the mass the slower the acceleration
The trolley should accelerate but slower than previously because…
Set distance
1Kg
FORCES AND ACCELERATION
Given the formula F = ma try the following questions.
1. What are the names and units of F, m and a?
2. Complete the table….
3. The rider and cycle are 150kg:
a. What is the Nett force?
b. What is the cyclist’s acceleration?
4. A bike accelerates at 10ms-2 using a force of 6000N. The rider is 70kg. What is the mass of the bike?
F m A
a. 9kg 0.5ms-2
6N 0.2kg b.
c. 800g 1.5ms-2
350N d. 15ms-2
e. 1200kg 0.015ms-2
800N150N
WEIGHT FORCE
Weight is a force. It is therefore measured in…
An object’s weight depends on two things…
Newtons (N)
Gravity
• varies depending where you are
• 10ms-2 or 10N/Kg on Earth
Mass
• does not vary
• measured in Kg
•A man with mass of 75Kg on earth weighs 750N
BUT on the moon he weighs 125N
The Source of Friction
Friction- A force that opposes motion between 2 surfaces that are touching
Friction occurs because the surface of any object is rough.
The amount of friction depends upon many factors like: Roughness of the surfaces Force pushing the surfaces together
FRICTION
Friction can be reduced by…
lubrication,
streamlining (aerodynamics),
slowing down,
smoothing surfaces
Newton’s 3rd Law of Motion
For every action there is an equal and opposite re-action.
Ex: Rocket Launching, Walking
UP, UP, and AWAY!
Waves
Waves: a disturbance that travels through a medium from one location to another often transferring energy
Transverse: causes vibration in the medium in a perpendicular direction to its own motion. Example: Light, Electromagnetic spectrum
Longitudinal: have vibrations along or parallel to their direction of travel. Example: Sound
Waves Wavelength: the distance between adjacent
crests, measured in meters. Period: the time it takes for one complete wave
to pass a given point, measured in seconds. Frequency: the number of complete waves that
pass a point in one second, measured in inverse seconds, or Hertz (Hz).
As frequency increases, Wavelength decreases
Waves
Refraction: the change indirection of a wave due to a change in its speed.
Wave speed varies in different media. Sound waves travel faster in water than air.
(Sonar) Light waves travel faster in air than water.
Electromagnetic Spectrum
Visible Light: ROY G BIV (Red has longer wavelength.)
The range of all possible electromagnetic radiation.
What kind of electromagnetic radiation has the shortest wavelength? The longest?
What kind of electromagnetic radiation could be used to "see" molecules? A cold virus?
Why can't you use visible light to "see" molecules? Some insects, like bees, can see light of shorter
wavelengths than humans can see. What kind of radiation do you think a bee sees?
Science of Light
Translucent: light can travel through Transparent : some light can travel through Opaque : no light can travel through
Earthquakes Making Waves Seismic waves carry energy from an
earthquake away from the focus, through Earth’s interior and across the surface.
Seismic Waves Primary (P waves): can travel through all states of
matter through compressions and rarefactions much like an accordion.
Secondary (S waves): cannot move through liquids; move back and forth and up and down (transverse wave)
Surface waves: when P and S waves reach the surface Love wave: rolls like a
wave Rayleigh wave: shakes
side to side