PROBLEM I (questions 1-6)A ball is thrown straight up in the air with a velocity of 40 m/s.1)What is the speed of the ball right before it hits the ground? (neglecting air resistance)speed = 0 m/s

speed = 10 m/s

speed = 20 m/s

speed = 40 m/s

speed = 80 m/s

2)How long will the ball be in the air?Time = 3.57 s

Time = 8.16 s

Time = 12.46 s

Time = 20 s

Time = 40 s

3)How high will the ball go?Height = 40.0 m

Height = 52.5 m

Height = 66.1 m

Height = 75.0 m

Height = 81.6 m

4)After 6 s, what is the position of the ball? (above the ground)Position = 0 m

Position = 21.6 m

Position = 40.6 m

Position = 63.6 m

Position = 81.6 m

5)After 6 s, what is the velocity of the ball? (assume up is the positive direction)-40.0 m/s

-18.8 m/s

0 m/s

18.8 m/s

40.0 m/s

6)After 6 s, what is the acceleration of the ball? (assume up is the positive direction)-40 m/s2

-9.8 m/s2

0 m/s2

+9.8 m/s2

+40 m/s2

PROBLEM II (question 7)Car A leaves town heading east with a constant speed of 20 miles/hr. An hour later car B leaves town heading east as well, with a constant speed of 25 miles/hr. 7)How long after car B leaves will it intercept car A?Half an hour later

Two hours later

Three hours later

Four hours later

Five hours later

This graph shows the velocity of an object versus time.8)Over which time interval is the object moving at constant velocity?t = 0 s to t = 1.5 s

t = 1.5 s to t = 3 s

t = 3 s to t = 4 s

t = 4 s to t = 5 s

9)At which time does the object change its direction of motion?1.5 s

3 s

4 s

5 s

None of the above

10)What is the acceleration over the first second?0 m/s2

5 m/s2

6.67 m/s2

10 m/s2

20 m/s2

11)What is the net displacement of the object after 6 seconds?positive

zero

negative

12)At what time is the object farthest from the starting point?1.5 s

3 s

4 s

5 s

6 s

13)What is the acceleration at 2 s and 4 s, respectively?positive, negative

positive, zero

positive, positive

negative, negative

negative, zero

negative, positive

zero, negative

zero, zero

zero, positive

An oarsman can row his boat 3 mph in still water. He sets out on the Illinois River, which flows at 5 mph. We are interested in what an observer on shore measures.14)When the man heads the boat directly downstream and rows as fast as he can, how fast does the observer on shore see the boat going?2 mph

3 mph

5 mph

7 mph

8 mph

15)When the man heads the boat directly downstream and rows as fast as he can, which direction does the observer on shore see the boat going?upstream

downstream

the observer sees the boat standing still!

Quiz 02A pickup truck starts from rest and maintains a constant acceleration a0. After a time t0, the truck is moving with speed 25 m/s at a distance of 120 m from its starting point. When the truck has travelled a distance of 60 m from its starting point, its speed is v1 m/s. 1) Which of the following statements concerning v1 is true?v1 < 12.5 m/s

v1 = 12.5 m/s

v1 > 12.5 m/s

2)When the truck has travelled for a time t2 = t0/2, its distance from its starting point is s2. Which of the following statements concerning s2 is true?s2 < 60 m

s2 = 60 m

s2 > 60 m

3)How long does it take for the pickup to reach its speed of 25 m/s?t0 = 3.1 s

t0 = 4.8 s

t0 = 6.8 s

t0 = 9.6 s

t0 = 13.4 s

The next two questions concern the graph shown below. This graph shows v, the one-dimensional velocity of a cart, as a function of time. The cart started its motion from rest at position x = 0.

4)Which of the following statements about a2.5, the acceleration of the cart at time t = 2.5 s?, is true?a2.5 < 0

a2.5 = 0

a2.5 > 0

5)Which of the following statements about x3, the position of the cart at time t = 3 s?, is true?x3 < 0

x3 = 0

x3 > 0

Two boats, each capable of moving in still water at a constant velocity v = 6 m/s, set out to cross a river of width W = 20 m. Boat 1 heads directly across the river while boat 2 is pointed at an angle = 60 degrees with respect to the shore as shown in the diagram below. The current in the river moves at speed v0 = 2 m/s as shown. The next three questions pertain to this situation.

6) Which boat takes the least amount of time to cross the river?Boat 1 takes the least time.

Boat 2 takes the least time.

Each boat takes the same amount of time.

7)Which boat moves with the greater speed with respect to the shore?Boat 1 moves with the greater speed with respect to the shore.

Boat 2 moves with the greater speed with respect to the shore.

They both move at the same speed with respect to the shore.

8)How far downstream (D) is boat 2 when it reaches the other side of the river? D = 7.1 m

D = 7.9 m

D = 10.0 m

D = 14.6 m

D = 19.3 m

Two projectiles are launched from a cliff of height H = 16m as shown in the diagram below. Projectile 1 is launched with velocity v1 = 12 m/s at an angle , where = 35 degrees. Projectile 2 is launched with velocity v2 = 12 m/s at an angle , where = 50 degrees. The next six questions pertain to this physical situation.

9)If the projectiles are lauched at the same time, which projectile lands first?Projectile 1 lands first.

Projectile 2 lands first.

The projectiles land at the same time.

10)What is the maximum height of projectile 2 above the ground?(not from the top of the cliff) y = 7.9 m

y = 11.3 m

y = 20.3 m

y = 26.0 m

y = 38.4 m

11)At the top of projectile 2's path, what is its speed? v = 0 m/s

v = 5.6 m/s

v = 7.7 m/s

v = 9.8 m/s

v = 12.0 m/s

12)How far from the cliff does projectile 2 land from the base of the cliff?x = 19.1 m

x = 22.9 m

x = 27.5 m

x = 30.1 m

x = 31.3 m

13)Right before projectile 2 hits the ground, what is its speed? v = 0 m/s

v = 12.0 m/s

v = 18.7 m/s

v = 21.4 m/s

v = 30.3 m/s

14)Which projectile lands farther away?Projectile 1 lands farther away.

Projectile 2 lands farther away.

The projectiles land at the same distance from the cliff.

15)A car's initial velocity is along the -x (negative x) direction. As it slows to a stop, its acceleration:is zero

points in the +x direction

points in the -x direction

Quiz 03An elevator is ascending at a constant velocity. A block of mass m is suspended from the ceiling of the elevator by a rope, as shown in the figure.

1) Which of the following is true of the magnitude of the tension T in the rope?T = mg

T < mg (but greater than zero)

T > mg

T = 0

Now assume the elevator is accelerating upward with a constant non-zero acceleration. 2)Which of the following is true of the magnitude of the tension T in the rope?T = mg

T < mg (but greater than zero)

T > mg

T = 0

Now assume the elevator is accelerating down with a constant non-zero acceleration. 3)Which of the following is true of the magnitude of the tension T in the rope?T = mg

T < mg (but greater than zero)

T > mg

T = 0

Finally, assume the elevator is in "free-fall" (accelerating down with acceleration -9.8 m/s2). 4)Which of the following is true of the magnitude of the tension T in the rope?T = mg

T < mg (but greater than zero)

T > mg

T = 0

A block of mass 5 kg is suspended by two ropes as shown in the picture below. The angle that the right rope makes with the horizontal is = 45 degrees.

5)Compare the tensions in the two ropes.Tright < Tleft

Tright = Tleft

Tright > Tleft

6)What is the tension in the left rope?T = 0 N

T = 29 N

T = 49 N

T = 55 N

T = 57 N

7)If the mass of the block was increased the tension in the left rope wouldIncrease

Decrease

Remain the same

A ball is swung in a horizontal circle (A view from above is shown below).

8)If the string is cut at the moment shown, which path will the ball take?

A

B

C

D

E

Three boxes are at rest on a table top as shown below.

9)What is true about the acceleration of the system?It is zero.

It is upward.

It is downward.

10)What is true about the net force on each block?All are zero.

All are upward.

All are downward.

It is different for each block.

11)Compare the magnitude of the force the 2 kg block exerts on the 1 kg block with the magnitude of the force the 1 kg block exerts on the 2 kg block.The forces are the same.

The force the 2 kg block exerts on the 1 kg block is less than the force the 1 kg block exerts on the 2 kg block.

The force the 2 kg block exerts on the 1 kg block is greater than the force the 1 kg block exerts on the 2 kg block.

12)What is the force that the table exerts on the 3 kg block?0 N

9.8 N

19.6 N

29.4 N

39.2 N

49 N

58.8 N

A box with mass M is pulled across a frictionless surface with a constant force F as shown below.

13)What is horizontal acceleration of the box?Mg

g

F

F/M

M

F/g

14)What is the normal force on the box?Mg

g

F

F/M

M

F/g

15)After the block is accelerated for 5 s, the force stops pulling on the box. What happens?The block comes to rest.

The block continues in the same direction with a constant speed.

The block continues to accelerate.

It depends on the values of F and M.

Quiz 04Two blocks are being pushed across a horizontal floor with a coefficient of kinetic friction =.3 . The mass of block A is 3kg, and the mass of block B is 2 kg.

1) If the force being applied by the finger is F, what is the force that block A applies to block B?FAonB = F

FAonB = F/2

FAonB = 2F/5

2)If the force applied by the finger is F=20N, what is the acceleration of the blocks?a = .68 m/s2

a = .94 m/s2

a = 1.06 m/s2

3)If the force applied by the finger was doubled, the acceleration of the blocks would be:less than twice as much

exactly twice as much

more than twice as much

A block of mass 3.3 kg is suspended by two ropes as shown in the picture below. The angle that the left rope makes with the horizontal is = 40 degrees.The angle that the right rope makes with the horizontal is = 30 degrees.

4)What is the tension in the left rope?T1 = 16.5 N

T1= 22.4 N

T1= 29.8 N

5)What is the tension in the right rope?T2 = 26.4 N

T2 = 30.2 N

T2 = 33.1 N

6)If the maximum tension EITHER rope can withstand is 50 N, what is the maximum mass that can be supported in this situation?5.54 kg

8.94 kg

12.3 kg

A cart with a mass of 20kg is initially at rest on a horizontal frictionless surface and is attached to a block of 5kg hanging vertically.

7)When the blocks are released and accelerating, what is the tension in the rope?T = 25 N

T = 39 N

T = 49 N

8)If the block was initially hanging 2m above the ground, what is the final velocity of the block right before it hits the ground?v = 1.6 m/s

v = 2.1 m/s

v = 2.8 m/s

9)If ONLY the mass of the cart was doubled, then the tension in the rope as the block was falling would...remain the same

decrease

increase

10)What coefficient of friction between cart and surface would be needed to keep the system from accelerating? (Using 20 kg as the mass of the cart.)0.20

0.25

0.50

11)In this situation (with friction), how does the tension in the rope compare with the weight of the hanging block?they are equal

the tension is greater than the weight of the block

the tension is less than the weight of the block

A block with mass M = 4 kg is held against a vertical wall by a horizontal force F = 75 N. The wall has coefficient of static friction = .6.

12)What is the normal force exerted by the wall on the block?39.2 N

23.52 N

75 N

13)What is the weight of the block?39.2 N

23.52 N

75 N

14)What is the force of friction holding the block up?39.2 N

23.52 N

75 N

15)The force F is reduced to only 60 N and it is seen that the block accelerates down with a = 2 m/s2. What is the coefficient of kinetic friction between the block and the wall?.30

.52

.74

Quiz 051)A planet has twice the mass of the earth but the same radius. What is the acceleration of gravity on the surface of this planet?the same as on earth

half as much as on earth

one-forth as much as on earth

twice as much as on earth

four times as much as on earth

2)A planet has twice the radius of the earth but the same mass. What is the acceleration of gravity on the surface of this planet?the same as on earth

half as much as on earth

one-forth as much as on earth

twice as much as on earth

four times as much as on earth

A satellite orbits the earth at a distance equal to twice the earth's radius above the surface of the earth (the total distance from the center of the earth is three times the radius of the earth). 3)The satellite has a mass of 60 kg. What is the force of attraction between the earth and the satellite?588 N

318 N

65.3 N

21.0 N

7.26 N

4)What is the centripetal acceleration of the satellite?88.2 m/s2

29.4 m/s2

9.80 m/s2

3.27 m/s2

1.09 m/s2

5)With what speed must the satellite move to follow a circular orbit?4565 m/s

1987 m/s

567 m/s

222 m/s

18 m/s

6)If the mass of the satellite was increased, what would need to happen to the speed to keep the same radius of orbit?increase

decrease

remain the same

A block is swung around in a vertical circle. 7)If the mass of the block is 2 kg, the radius of the circle is 0.8 m, and the speed of the block is 3 m/s, what is the tension in the string at the top of the circle?2.9 N

3.6 N

4.8 N

6.1 N

7.7 N

8)Is the tension greater or less or equal at the bottom of the circle?greater at the bottom

less at the bottom

the same at the bottom

9)If the velocity was increased, the tension at the top would:increase

decrease

remain the same

10)If the radius was increased, the tension would:increase

decrease

remain the same

A car drives on a road which begins flat, then goes up and over the top of a hill and then goes down into a dip and back up to level ground. 11)Compare the magnitude of the normal force acting on the car at each point:Nflat > Ntop of hill > Nbottom of dip

Nflat > Nbottom of dip > Ntop of hill

Nbottom of dip > Ntop of hill > Nflat

Nbottom of dip > Nflat > Ntop of hill

Ntop of hill > Nbottom of dip > Nflat

Ntop of hill > Nflat > Nbottom of dip

12)If the car is moving at 30 m/s at the bottom of the dip, its mass is 800 kg, and the radius of curvature for the dip is 20 m, what is the normal force acting on the car in the dip.10459 N

19344 N

28625 N

37190 N

43840 N

13)What is the acceleration of the car at the bottom of the dip?0 m/s2

9.8 m/s2

35.2 m/s2

45.0 m/s2

54.8 m/s2

14)What is the minimum speed at the top of the hill (assuming R = 20 m here, too) for the car to leave the road?10 m/s

12 m/s

14 m/s

16 m/s

18 m/s

15)What is the acceleration of the car if it just begins to leave the road?0 m/s2

4.9 m/s2

9.8 m/s2

14.7 m/s2

19.6 m/s2

Quiz 06Top of FormA 3 kg box is pushed across a frictionless horizontal floor with a force F = 20 N that makes an angle of 25 with the horizontal. The box moves 18 m. 1)What is the work done by the force F? 529 J 360 J 326 J 210 J 0 J2)What is the work done by the force of gravity acting on the box? 529 J 360 J 326 J 210 J 0 J3)What is the work done by the normal force acting on the box? 529 J 360 J 326 J 210 J 0 J4)If the box starts at rest, what is the final speed of the box? 12.3 m/s 14.7 m/s 16.0 m/s 18.0 m/s 21.9 m/sA 3 kg box is pushed across a horizontal floor WITH FRICTION by a force F = 20 N that is parallel to the floor. The box moves 18 m. The box moves with CONSTANT SPEED. 5)What is the work done by the force F? 529 J -529 J 360 J -360 J 0 J6)What is the work done by the force of friction acting on the box? 529 J -529 J 360 J -360 J 0 JA skier with a mass of 50 kg starts from the top of a hill (at rest) at height h above ground. The skier glides down the hill to point A where her velocity is vA = 20 m/s and continues up a second hill 8 meters high and back down the other side. Her entire trip up to point C is frictionless. At point C she begins stopping and comes to a complete stop 48 meters later at point D.

7)What is the height h of the first hill? h = 12.8 m h = 32.5 m h = 16.5 m h = 28.6 m h = 20.4 m8)What is the speed of the skier at point B? 0 m/s 12.8 m/s 15.6 m/s 18.3 m/s 20 m/s9)What is the speed of the skier at point C? 0 m/s 12.8 m/s 15.6 m/s 18.3 m/s 20 m/s10)When coming down the first hill, at what height off the ground will the SPEED of the skier be half of its value at point A? at a distance h off the ground at a distance .75h off the ground at a distance .5h off the ground at a distance .25h off the ground11)What is the magnitude of the work done by friction on the skier in stopping her? W = 10000 J W = 11200 J W = 12300 J W = 12300 J W = 12300 J 12)What is the coefficient of friction in the region from C to D? .425 .587 .615 .736 .82213)If the mass of the skier were doubled how would the speed at point A change? increase remain the same decrease14)If the mass of the skier were doubled how would the stopping distance change? increase remain the same decrease15)If the mass of the skier were doubled how would the magnitude of the work done by friction change? increase remain the same decrease Bottom of Form