IB Energy Test Review(Answer Key on page 5)
Multiple Choice
Identify the choice that best completes the statement or answers the question.
____1.From the top of a high cliff, a ball is thrown horizontally with initial speed v0. Which of the following graphs best represents the ball’s kinetic energy K as a function of time t?
a. / / c. / / e. /b. / / d. /
____2.A person pushes a box across a horizontal surface at a constant speed of 0.5 meter per second. The box has a mass of 40 kilograms, and the coefficient of sliding friction is 0.25. The power supplied to the box by the person is
a. / 0.2 W / b. / 5 W / c. / 50 W / d. / 100 W / e. / 200 WA ball swings freely back and forth in an arc from point I to point IV, as shown above. Point II is the lowest point in the path, III is located 0.5 meter above II, and IV is 1 meter above II. Air resistance is negligible.
____3.If the potential energy is zero at point II, where will the kinetic and potential energies of the ball be equal?
a. / At point II / d. / At some point between III and IVb. / At some point between II and III / e. / At point IV
c. / At point III
____4.The speed of the ball at point II is most nearly
a. / 3.0 m/s / b. / 4.5 m/s / c. / 9.8 m/s / d. / 14 m/s / e. / 20 m/s____5.
The figure above shows a rough semicircular track whose ends are at a vertical height h. A block placed at point P at one end of the track is released from rest and slides past the bottom of the track. Which of the following is true of the height to which the block rises on the other side of the track?
a. / It is equal to h/2.b. / It is equal to h/4.
c. / It is equal to h/2.
d. / It is equal to h.
e. / It is between zero and h; the exact height depends on how much energy is lost to friction.
____6.A weight lifter lifts a mass m at constant speed to a height h in time t. What is the average power output of the weight lifter?
a. / mg / b. / mh / c. / mgh / d. / mght / e. / mgh/tA plane 5 meters in length is inclined at an angle of 37°, as shown above. A block of weight 20 newtons is placed at the top of the plane and allowed to slide down.
____7.The work done on the block by the gravitational force during the 5-meter slide down the plane is most nearly
a. / 20 J / b. / 60 J / c. / 80 J / d. / 100 J / e. / 130 J____8.Units of power include which of the following?
I.wattII.joule per secondIII.kilowatt·hour
a. / I only / c. / I and II only / e. / I, II, and IIIb. / III only / d. / II and III only
____9.
A block of mass 3.0 kg is hung from a spring, causing it to stretch 12 cm at equilibrium, as shown above. The 3.0 kg block is then replaced by a 4.0 kg block, and the new block is released from the position shown above, at which the spring is unstretched. How far will the 4.0 kg block fall before its direction is reversed?
a. / 9 cm / b. / 18 cm / c. / 24 cm / d. / 32 cm / e. / 48 cmA rock of mass m is thrown horizontally off a building from a height h, as shown above. The speed of the rock as it leaves the thrower's hand at the edge of the building is v0.
____10.What is the kinetic energy of the rock just before it hits the ground?
a. / / c. / / e. /b. / / d. /
____11.When a block slides a certain distance down an incline, the work done by gravity is 300 J. What is the work done by gravity if this block slides the same distance up the incline?
a. / 300 Jb. / Zero
c. / –300 J
d. / It cannot be determined without knowing the distance the block slides.
e. / It cannot be determined without knowing the coefficient of friction.
____12.
A small block is released from a height of 12 m as shown. Assuming a frictionless track, compute the maximum value of R in order for the block to go around the loop without losing contact with the track.
a. / 12 m / b. / 8 m / c. / 6 m / d. / 4.8 m / e. / 4 m____13.A student pushes a block up a frictionless incline at constant speed by pushing on it with a horizontal force. As it moves up the incline its motion is subject to the influences of the weight force, the normal force, and the force of the push. We know the work done on the block by the normal force is zero because:
a. / The kinetic energy of the block does not change.b. / The normal force is always directed perpendicular to the block’s motion.
c. / The work done by the weight force equals the work done by the push force.
d. / The momentum of the block is constant.
e. / The force of the momentum is constant.
____14.
A 2.0-kg particle moves along the x-axis from x = 0 to x = 4 m subject to the force shown in the graph. The work done on the particle by this force is
a. / 18 J / b. / 23 J / c. / 28 J / d. / 33 J / e. / 37 J____15.Which of the following forces is not a conservative force?
a. / Friction / c. / Gravitational / e. / Not hereb. / Elastic / d. / Electric
____16.W is the amount of work done to stretch a spring a distance x. If instead the spring were stretched by an amount 2x, the work done would be
a. / 2W / b. / 4W / c. / 8W / d. / 16W / e. /IB Energy Test Review
Answer Section
MULTIPLE CHOICE
1.ANS:EPTS:1TOP:Energy
2.ANS:CPTS:1TOP:Energy
3.ANS:CPTS:1TOP:Energy
4.ANS:BPTS:1TOP:Energy
5.ANS:EPTS:1TOP:Energy
6.ANS:EPTS:1TOP:Energy
7.ANS:BPTS:1TOP:Energy
8.ANS:CPTS:1TOP:Energy
9.ANS:DPTS:1TOP:Energy
10.ANS:DPTS:1TOP:Energy
11.ANS:CPTS:1TOP:Energy
12.ANS:DPTS:1TOP:Energy
13.ANS:BPTS:1TOP:Energy
14.ANS:DPTS:1TOP:Energy
15.ANS:APTS:1TOP:Energy
16.ANS:BPTS:1TOP:Energy