Two objects are at rest on a frictionless surface. Object 1 has a mass that is twice that of Object 2. When a constant force is applied to Object 1, it accelerates for a time interval t. The force is removed from Object 1 and is then applied to Object 2. After Object 2 has been accelerated for the same time interval, which statements are true?
(i) p2 = 2p1
(ii) p2 = p1
(iii) p2 = p1
(iv) KE2 = 2KE1
(v) KE2 = KE1
(vi) KE2 = KE1
1.(i) and (vi)
2.(ii) and (iv)
3.(i) and (v)
4.(iii) and (v)
[Ques. 2] Two objects are at rest on a frictionless surface. Object 1 has a mass that is twice that of Object 2. When a constant force is applied to Object 1, it accelerates through a distance d. The force is removed from Object 1 and is then applied to Object 2. At the moment when Object 2 has accelerated through the same distance d, which statements are true?
(i) p2 = 2p1
(ii) p2 = p1
(iii) p2 = p1
(iv) KE2 = 2KE1
(v) KE2 = KE1
(vi) KE2 = KE1
1.(i) and (iv)
2.(ii) and (vi)
3.(i) and (v)
4.(iii) and (v)
[Ques. 3] A car and a large truck make a head-on collision and stick together. Prior to the collision, the truck's velocity was twice that of the car. Which vehicle experiences the larger change in the magnitude of its momentum?
1.the car
2.the truck
3.Both vehicles experience the same magnitude change in momentum.
4.Impossible to determine.
[Ques. 4] A boulder falls off a cliff toward the ground with no air resistance. The isolated system for which momentum is conserved is
1.only the Earth.
2.only the boulder.
3.both the Earth and the boulder.
4.none of these.
[Ques. 5] Your gym teacher throws a large and heavy medicine ball to you for you to catch. She is next going to throw to you a baseball that has a mass that is one tenth of that of the medicine ball. You are given the following choices. You can have the baseball thrown with
(i) the same speed as the medicine ball,
(ii) the same momentum as the medicine ball, or
(iii) the same kinetic energy as the medicine ball.
Rank these choices from the slowest to the fastest speed of the baseball.
1.(i), (ii), (iii)
2.(i), (iii), (ii)
3.(ii), (iii), (i)
4.(iii), (ii), (i)
[Ques. 6] Object 1 has more kinetic energy than Object 2. How do the magnitudes of their momenta compare?
1. p1 = p2
2. p1 > p2
3. p1 p2
4. not enough information given to tell
[Ques. 7] In the case of a force varying with position, what feature of the graph of force vs. position represents the work done during a displacement?
1.the maximum force times the maximum position
2.the beginning force times the total displacement
3.the area under the curve
4.nothing
[Ques. 8] A ball is thrown straight up in the air. At what position is its kinetic energy a maximum? At what position is the gravitational potential energy of the ball-Earth system a maximum? Consider only the trip up.
1.The maximum kinetic energy occurs at the top of the ball's trajectory and the maximum gravitational potential energy occurs at the top of the ball's trajectory.
2.The maximum kinetic energy occurs at the point of release and the maximum gravitational potential energy occurs at the point of release.
3.The maximum kinetic energy occurs at the point of release and the maximum gravitational potential energy occurs at the top of the ball's trajectory.
4.The maximum kinetic energy occurs at the top of the ball's trajectory and the maximum gravitational potential energy occurs at the point of release.
[Ques. 9] You are working in a library, reshelving books. You lift a book from the floor to the top shelf. The kinetic energy of the book on the floor was zero, and the kinetic energy of the book on the top shelf is zero, so there is no change in kinetic energy. Yet you did some work in lifting the book. Is the work-kinetic energy theorem violated?
1.Yes, it is violated because a force acting on the book should change the book's kinetic energy.
2.No, it is not violated because the book really does have a final velocity, but so does the entire system, so it is impossible to detect the book's motion.
3.Yes, it is violated because a force that acts on the book should change the book's velocity.
4.No, it is not violated because there are two forces that act on the book. One is the downward force that the Earth exerts on the book, which is counterbalanced by the upward force that you exert on the book. The total work done on the book, therefore, is zero, and is equal to its overall change in kinetic energy.
[Ques. 10] If 3 different conservative forces and one non-conservative force act within a system, how many potential energy terms appear in the energy equation that describes the system?
1.0
2.1
3.3
4.4
Quick Reply
