Download Pre-Test - Aurora City Schools

Physics
Ch 9 Energy
Pre-Test
1. If you lift a load of books up two stories, how much work have you done compared to lifting a load of
books up one single story?
a. One quarter as much
b. Half as much
c. The same amount
d. Twice as much
e. Four times as much
2. If Nellie Newton pushes an object with twice the force for twice the distance, she does…
a. Twice the work
b. Four times the work
c. Eight times the work
d. The same amount of work
3. An object that has kinetic energy must also have
a. Acceleration
b. A force applied to it
c. Momentum
d. Potential energy
4. Which of the following statements is NOT true regarding potential energy?
a. The higher an object is, the more potential energy it will have
b. Potential energy is lost as a stretched object returns to its original shape
c. Potential energy depends on the mass of an object
d. Potential energy can be measured in Joules
5. A 1200 kg car and a 2400 kg car are lifted at a constant speed to the same height in an auto shop. Lifting
the more massive car requires __________ work.
a. Less
b. The same
c. Twice as much
d. Four times as much
e. More than four times as much
6. If air resistance is negligible, the sum total of potential and kinetic energy for a freely falling body will be
a. Increasing
b. Decreasing
c. Constant
d. Zero
7. The potential energy of a box on a shelf , relative to the floor, is a measure of
a. The amount of work that needed to be done to move the box from the floor to the shelf
b. The weight of the box multiplied by the height off the floor
c. The amount of kinetic energy the box would have upon impact with the floor if it were allowed to
fall from the shelf
d. All of these
8. The law of conservation of energy states that
a. Energy must be conserved and you are breaking the law if you waste energy
b. The supply of energy is limited so we must conserve
c. The total amount of energy remains constant
d. Energy cannot be used faster than it is created
9. If the amount of stretch in a spring is tripled, the energy stored in the string would be
a. One third as much
b. Three times as great
c. Nine times as great
d. Twenty-seven times as great
10. Work is always done when a force
I. acts vertically on a box moving along a horizontal surface.
II. exerted on one end of a box is equal and opposite to a force exerted on the other end of the box.
III. pushes a box up an incline.
IV. of gravitational attraction acts between a box and the surface of the earth.
a. I and II
b. II and IV
c. I only
d. III only
Consider the data presented below for questions 11-13.
Object A
Object B
Mass (kg)
5.0
10.0
Velocity (m/s)
4.0
2.0
Height (m)
2.0
3.0
Object C
1.0
5.0
5.0
Object D
5.0
2.0
4.0
11. Rank the objects from smallest to largest kinetic energy.
12. Rank the objects from smallest to largest potential energy.
13. Rank the objects from smallest to largest mechanical energy.
14. A skydiver falls to the earth at a constant speed due to air resistance. Where does the lost potential
energy go?
15. A child jumps up and down on a trampoline. Describe the changes in energy that occur during one
complete cycle of this process starting. Start the description from the moment the child is at peak height
in the jump.
16. A 0.25 kg baseball is dropped from a height of 2.0 m. Use energy relationships to determine the speed as
it hits the ground.
17. How much work is done in lifting a 12 kg block of ice a vertical distance of 1.5 m?
18. Determine the spring constant of a spring that stores 750 J of energy when stretched a distance of 0.32
m?
19. A 0.20 kg hockey puck is brought to rest by friction with the ice. If the puck slows to a stop from its initial
speed of 12 m/s over a distance of 8.0 m, use the work energy theorem to determine the force of friction
on the puck?