1. Which of the Following Is the Best Example of Work Being Done on an Object?

Name: ______Date: ______

Quarter 2: MCAS Review

1. Which of the following is the best example of work being done on an object?

A.holding a 50 kg barbell

B.lifting a bag of groceries

C.keeping a board in place

D.pushing on a car that will not move

2. A man applies a force of 100 N to a rock for 60 seconds, but the rock does not move. What is the amount of work done by the man on the rock?

A.0.0 J

B.6.0 J

C.100 J

D.6000 J

3. Four students of different weights timed themselves walking up a set of stairs.

Which student used the most power while walking up the stairs?

A.student W

B.student X

C.student Y

D.student Z

4. The figure below represents a pendulum’s motion with the lowest point of its swing labeled P.

What happens to most of the pendulum’s gravitational potential energy as it reaches the lowest point P?

A.It is transformed into inertia.

B.It is transformed into kinetic energy.

C.It is transformed into thermal energy.

D.It is transformed into chemical energy.

5. A 1 kg block sliding to the right on a level, frictionless surface with a speed of 2 m/s collides and sticks to a second 1 kg block sliding to the left.

After the collision, the blocks are motionless. What was the speed of the second 1 kg block before the collision?

A.1 m/s

B.2 m/s

C.3 m/s

D.4 m/s

6. Which of the following has the greatest momentum?

A.a 60 kg deer moving west at a speed of 16.4 m/s

B.a 6300 kg elephant moving east at a speed of 0.11 m/s

C.a 0.42 kg soccer ball moving downfield at a speed of 12 m/s

D.a 0.03 kg arrow moving toward a target at a speed of 150 m/s

7. Three different boxes are lifted to different heights.

Which of the following statements best describes the boxes’ change in mechanical energy?

A.Box X had the greatest change in mechanical energy

B.Box Z had the smallest change in mechanical energy.

C.Boxes X and Y had the same change in mechanical energy.

D.Boxes Y and Z had the same change in mechanical energy.

8. Mike, who has a mass of 75 kg, is running north at 2.6 m/s. He accidentally collides with Tom, who has a mass of 125 kg and is not moving.

Which of the following statements describes how much momentum each person has before the collision?

A.Mike has a momentum of 130 kg • m/s north, and Tom has no momentum.

B.Mike has a momentum of 195 kg • m/s north, and Tom has no momentum.

C.Both Mike and Tom have a momentum of 130 kg • m/s north.

D.Both Mike and Tom have a momentum of 195 kg • m/s north.

9. How much power is required to carry a 35 N package a vertical distance of 18 m if the work on the package is accomplished in 30 s?

A.16 W

B.21 W

C.58 W

D.630 W

10. Which of the following increases when a metal spring is stretched horizontally?

A.potential energy

B.kinetic energy

C.gravitational energy

D.electrical energy

11. An engineering student is gathering data on the motion of a model car traveling down a ramp. If energy is conserved, the potential energy of the car at the top of the ramp should equal the kinetic energy of the car at the bottom of the ramp. After the first trial, the student calculates that the kinetic energy at the bottom of the ramp is less than the potential energy at the top of the ramp.

Which of the following can best explain this difference?

A.The car gained a small amount of mass as it moved down the ramp.

B.The student accidentally accelerated the car at the top of the ramp.

C.The measured height of the ramp was less than the actual height.

D.The student did not include the effect of frictional force in the calculation.

12. What is the momentum of a metal disc with a mass of 1.5 kg sliding on a frictionless surface at 0.75 m/s?

A.0.50 kg • m/s

B.0.85 kg • m/s

C.1.1 kg • m/s

D.2.0 kg • m/s

13. The diagrams below show a cart moving with a velocity, V, on a frictionless surface as a wooden block is being dropped. The block then falls straight down onto the moving cart.

Which of the following statements describes what will happen after the block lands on the moving cart?

A.The cart will move to the left at a velocity less than the original velocity of the cart.

B.The cart will move to the left at a velocity greater than the original velocity of the cart.

C.The cart will move to the right at a velocity less than the original velocity of the cart.

D.The cart will move to the right at a velocity greater than the original velocity of the cart.

12. A cart at the top of a hill is released and rolls down the hill. Which of the following describes the energy of the cart just as it reaches the bottom of the hill?

A.The cart has no energy.

B.The cart has maximum kinetic energy.

C.The cart has maximum gravitational potential energy.

D.The cart has equal gravitational potential and kinetic energy.

13. A 600 g basketball, a 57 g tennis ball, a 46 g golf ball, and a 2.7 g table tennis ball are moving with the same velocity. Which ball has the greatest momentum?

A.golf ball

B.basketball

C.tennis ball

D.table tennis ball

14. The motor of one car is more powerful than the motor of another car. Which of the following must be true of the more powerful motor?

A.It can do work more quickly.

B.It can operate for a longer time.

C.It can burn fuel more efficiently.

D.It can store more potential energy.

15. A crane lifts two 100 kg loads of building materials to the top of a building under construction. The first load is lifted in 10 s and the second load is lifted in 13 s.

Which of the following statements best compares the work and power expended by the crane lifting the two loads?

A.The crane does more work and expends more power for the first lift.

B.The crane does the same work and expends the same power for each lift.

C.The crane does the same work for each lift but expends more power for the first lift.

D.The crane does more work in the second lift but expends the same power for each lift.

16. The diagram below shows an electrical circuit.

Which of the following best explains why energy stored in the battery power source diminishes over time when this circuit is complete?

A.Energy is destroyed when the light bulb operates.

B.The light bulb transforms energy into light and heat.

C.The light bulb converts the negative charge of electrons into light and heat.

D.The power source generates energy more slowly than the light bulb consumes it.

17. A 9 kg model airplane flies horizontally at a constant speed. If the plane suddenly dives from its altitude of 50 m and levels off at 20 m, how much potential energy does it lose in the dive?

A.450 J

B.1800 J

C.2700 J

D.9000 J

18. To calculate the momentum of a pickup truck with a velocity of 25 m/s east, it is also necessary to know which of the following?

A.time elapsed

B.drive force of the motor

C.mass of the pickup truck

D.distance that the pickup travels

19. A cart with a mass of 5 kg rests on a floor next to a wall, as shown in the diagram below.

A person pushes on the cart to the left toward the wall with a force of 100 N. Which of the following statements is true in this situation

A.The wall does not push on the cart.

B.The floor pushes 100 N up on the cart.

C.The cart pushes 100 N down on the floor.

D.The wall pushes 100 N to the right on the cart.

20. A hockey player swings her hockey stick and strikes a puck. According to Newton's third law of motion, which of the following is a reaction to the stick pushing on the puck?

A.the puck pushing on the stick

B.the stick pushing on the player

C.the player pushing on the stick

D.the puck pushing on the player

Name: ______Date: ______

Quarter 2: MCAS Review Homework

Answer on the back of this paper or on a separate piece of paper.

1. Two athletes are lifting weights. Athlete X lifts 445 N a distance of 2 m in 4 s. Athlete Y lifts 445 N a distance of 2 m in 1 s. Assume that each athlete lifts the weights over his head the same distance from the floor.

1. Calculate the amount of work each athlete does. Show your calculations and include units in your answer.
2. Compare the amounts of work done by the two athletes. Explain your answer.
3. Calculate the power each athlete uses. Show your calculations and include units in your answer.
4. Compare the power used by athlete X with the power used by athlete Y. Explain your answer.

2. The figure below shows a tennis ball bouncing from point 1 to point 5.

The tennis ball bounces up from point 1 as shown in the figure to a maximum height labeled as point 2. The ball then bounces a few times. Neglect any horizontal motion.

1. Describe the kinetic and gravitational potential energy changes of the ball that occur between points 1 and 2.
2. Describe the kinetic and gravitational potential energy changes of the ball that occur between points 2 and 3.
3. Compare the kinetic energy of the ball at points 3 and 4.
4. The tennis ball has less energy at point 5 than it had at point 3. Explain what happened to the energy the ball had at point 3.

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