Question: Select one: What is the correct weight of an object given the choices?

Answer Options:
a. 961.6 kg
b. 9048.4 kg
c. 6567 kg
d. 1813 kg

Answer: a. 961.6 kg

Question: A system is composed of two particles. One particle is located at (1, 1) and has a mass of 3.4 kg; the second particle is located at (−6.4, 5.8) and has a mass of 5.0 kg. Where is the x-component of the center of mass of the system located?

Answer Options:
a. −14.3
b. −3.4
c. −2.7
d. 4.2

Answer: b. −3.4

Question: Two identical boxes are moved in equal distances in the horizontal direction. Box A experiences a constant net force F applied at an angle θ to the horizontal and box B experiences a constant net force of 2F applied at an angle of 2θ to the horizontal. Which of the following is correct?

Answer Options:
a. More work is done on box A than on box B.
b. More work is done on box B than on box A.
c. The same amount of work is done on each box.
d. The amount of work done on each box cannot be determined from the data given.

Answer: d. The amount of work done on each box cannot be determined from the data given.

Question: Which of the following statements about an object’s center of mass is not true?

Answer Options:
a. It is the point where an object will balance.
b. The object acts as if all its mass were concentrated there.
c. It is always at the geometric center of the object.
d. It is always located inside the object.

Answer: d. It is always located inside the object.

Question: In a game of marbles, a 60 g marble is rolling at 8.00 cm/s when it collides with a stationary marble. The 60 g marble takes off at a 27° angle at a reduced speed of 4.89 cm/s. The second marble moves at a rate of 3.21 cm/s at a 31.7° angle. Which of the following is the mass of the second marble?

Answer Options:
a. 68.1 kg
b. 0.0681 kg
c. 0.0800 kg
d. 80.0 kg

Answer: c. 0.0800 kg

Question: Knowing an object’s center of mass is useful for which of the following?

Answer Options:
a. Determining an object’s motion
b. Balancing an object
c. Designing an airplane
d. All of the above

Answer: d. All of the above

Question: Evaluate the following as true or false. The only way to change angular momentum is to apply a torque.

Answer Options:
a. false
b. true

Answer: b. true

Question: Which of the following is not correct?

Answer Options:
a. Work occurs when a force is applied to an object through so that the object is moved some distance.
b. If a force is applied to an object but there is no displacement, then no work is done.
c. The work done by gravity is always negative.
d. The work done by a constant force is the product of the magnitudes of the parallel component of the force and the displacement.

Answer: c. The work done by gravity is always negative.

Question: Which of the following statements is true for any completely enclosed ideal fluid?

Answer Options:
a. As the pressure changes at one end, this pressure change diminishes as it reaches the walls and opposite end of the enclosure.
b. A pressure change at one end produces a direction-dependent pressure change in the other end.
c. An increase in pressure at one end of the enclosure causes a decrease in the pressure in the opposite end of the enclosure.
d. Any change in pressure is transmitted equally to all points in the fluid.

Answer: d. Any change in pressure is transmitted equally to all points in the fluid.

Question: Two rocket ships pass overhead, traveling in opposite directions at constant, high speeds. You see that the rocket ships both cut their engines off, and by taking various measurements you determine that the two ships turned off their engines at the same time. Meanwhile, a scientist on board one of the ships determines that he turns off his engines before the engines of the other ship turn off. Which of the following is correct?

Answer Options:
a. The observation of the scientist on the ship is not valid because he is not in an inertial reference frame.
b. Both your observation and the scientist’s observations are equally valid.
c. Your observation is invalid because both of the ships are in motion relative to you.
d. The observation of the scientist on the ship is not valid because the event of his rocket engines turning off moves along with his ship.

Answer: b. Both your observation and the scientist’s observations are equally valid.

Question: A rocket leaves the surface of the Earth and flies to a distance of one Earth radius above the surface of the Earth. What happens to both the gravitational force and potential energy of the rocket?

Answer Options:
a. The force increases by factor of 2. The potential energy decreases by factor of 2.
b. The force decreases by factor of 2. The potential energy increases by factor of 4.
c. The force increases by factor of 4. The potential energy decreases by factor of 2.
d. The force decreases by factor of 4. The potential energy increases by factor of 2.

Answer: d. The force decreases by factor of 4. The potential energy increases by factor of 2.

Question: If the radius of a pipe carrying water is doubled, the volume flow rate of the water ____________.

Answer Options:
a. remains the same
b. is quartered
c. is halved
d. is quadrupled

Answer: a. remains the same

Question: Two objects are rotating next to each other. The second has twice the mass and three times the radius, compared to the first. However, it is rotating only one-fifth as quickly. What is the ratio of the rotational kinetic energy of the first object to that of the second?

Answer Options:
a. 5/6
b. 25/18
c. 25/6
d. There is not enough information.

Answer: d. There is not enough information.