Physics 111 Exam 3 Questions and Correct
Answers
You are standing on a skateboard, initially at rest. A friend throws a very heavy ball
towards you. You can either catch the object or deflect the object back towards your
friend (such that it moves away from you with the same speed as it was originally
thrown). What should you do in order to MINIMIZE your speed on the skateboard?
A. Catch the ball
B. Deflect the Ball
C. . Your final speed on the skateboard will be the same regardless whether you catch
the ball or deflect the ball.
D. There is not enough information given to determine an answer
A. Catch the ball
In an INELASTIC collision between two objects
A. the momentum of the system is conserved but the kinetic energy of the system is not
conserved.
B. the momentum of each object is conserved
C. The kinetic energy of each object is conserved
D. Both the momentum and the kinetic energy of the system are conserved
A. the momentum of the system is conserved but the kinetic energy of the system is not
conserved.
A ball moves in a circular path on a horizontal, frictionless surface. It is attached to a
light string that passes through a hole in the center of the table. If the string is pulled
down, thereby reducing the radius of the path of the ball, the speed of the ball is
observed to increase. Which one of the following statements provides an explanation for
, this increase?
A. This follows form applying Newtons 3rd law of motion
B. The total mechanical energy of the ball must remain constant because energy is
conserved
C. The angular momentum of the ball is conserved in this process
D. When the string is pulled downward, the angular momentum must increase
C. The angular momentum of the ball is conserved in this process
A collision between two objects is elastic. Which one of the following statements
concerning this situation is true?
A. The total kinetic energy of the objects is the same before and after the collision
B. The total momentum of the objects is zero Kg*m/s after the collision
C. the vector sum of the velocities of the two objects is equal to zero m/s after the
collision
D. The objects stick together and move as one after the collision
A. The total kinetic energy of the object is the same before and after the collision
Complete the following statement: The center of mass is
a. the only point on an object at which the gravitational force acts.
b. the region of an object where most of the mass is located.
c. the point at the geometrical center of an object.
d. the point within an object that moves as if all of the object's mass were located there.
D. the point within an object that moves as if all of the objects mass were located there
The momentum of an object is not dependent on which one of the following quantities?
a. inertia
Answers
You are standing on a skateboard, initially at rest. A friend throws a very heavy ball
towards you. You can either catch the object or deflect the object back towards your
friend (such that it moves away from you with the same speed as it was originally
thrown). What should you do in order to MINIMIZE your speed on the skateboard?
A. Catch the ball
B. Deflect the Ball
C. . Your final speed on the skateboard will be the same regardless whether you catch
the ball or deflect the ball.
D. There is not enough information given to determine an answer
A. Catch the ball
In an INELASTIC collision between two objects
A. the momentum of the system is conserved but the kinetic energy of the system is not
conserved.
B. the momentum of each object is conserved
C. The kinetic energy of each object is conserved
D. Both the momentum and the kinetic energy of the system are conserved
A. the momentum of the system is conserved but the kinetic energy of the system is not
conserved.
A ball moves in a circular path on a horizontal, frictionless surface. It is attached to a
light string that passes through a hole in the center of the table. If the string is pulled
down, thereby reducing the radius of the path of the ball, the speed of the ball is
observed to increase. Which one of the following statements provides an explanation for
, this increase?
A. This follows form applying Newtons 3rd law of motion
B. The total mechanical energy of the ball must remain constant because energy is
conserved
C. The angular momentum of the ball is conserved in this process
D. When the string is pulled downward, the angular momentum must increase
C. The angular momentum of the ball is conserved in this process
A collision between two objects is elastic. Which one of the following statements
concerning this situation is true?
A. The total kinetic energy of the objects is the same before and after the collision
B. The total momentum of the objects is zero Kg*m/s after the collision
C. the vector sum of the velocities of the two objects is equal to zero m/s after the
collision
D. The objects stick together and move as one after the collision
A. The total kinetic energy of the object is the same before and after the collision
Complete the following statement: The center of mass is
a. the only point on an object at which the gravitational force acts.
b. the region of an object where most of the mass is located.
c. the point at the geometrical center of an object.
d. the point within an object that moves as if all of the object's mass were located there.
D. the point within an object that moves as if all of the objects mass were located there
The momentum of an object is not dependent on which one of the following quantities?
a. inertia
