An instructor fires an arrow into a wooden block suspended by strings, as shown. If the mass of the arrow is 1/10 the mass of the block, what is the momentum of the arrow relative to the momentum of the block after the arrow has fully penetrated the block and is moving with it?
a. The same.
b. The momentum of the arrow is 1/10 that of the block.
c. The momentum of the arrow is ten times that of the block.
d. The momentum of the arrow is 100 times that of the block because the kinetic energy is mv2.
e. The momentum of the arrow is 1/100 times that of the block because the kinetic energy is mv2.
[Ques. 2] When you walk forward on a scooter that was previously at rest, how do you calculate the total momentum of you and the scooter?
a. You don't have to calculate it; you already know that it is zero.
b. You measure how far you move forward and how far the scooter moves backward, and average the two.
c. You measure how far you move forward and how far the scooter moves forward, and add the two.
d. You calculate the forces on the scooter in newtons by adding mass and acceleration.
e. You calculate the forces on the scooter in newtons by multiplying mass and acceleration.
[Ques. 3] If the momentum of the person is P, the momentum of the skateboard in the situation shown in the figure is:
a. P.
b. P.
c. zero.
d. 2P.
e. -2P.
[Ques. 4] Which of these is NOT a vector quantity?
a. momentum
b. impulse
c. displacement
d. speed
e. velocity
[Ques. 5] If the pole-vaulter were to land on concrete rather than on a cushion, the impulse that stops the fall would be:
a. greater because of the rigidity of the concrete.
b. greater because the force of impact is greater.
c. less, because there is less change in momentum during the stop.
d. less, because he would come to a stop over a shorter period of time.
e. the same because impulse is the change in momentum of the object.
[Ques. 6] Momentum is measured in:
a. kilograms per second.
b. meters per kilogram.
c. kilogram-meters per second.
d. kilogram-meters per second per second.
e. kilogram-seconds per meter.
[Ques. 7] What do we know about the direction of momentum?
a. It has the same direction as the object's speed.
b. It has the same direction as the object's acceleration.
c. It has the same direction as the object's weight.
d. It has the opposite direction to the object's velocity.
e. It has the same direction as the object's velocity.
[Ques. 8] Which has greater momentum in this photo: the non-moving ship or the kayak moving at the slow speed of 1 meter in ten seconds?
a. The ship because of its overwhelmingly greater mass.
b. The kayak because it has non-zero momentum while the ship at rest must have zero momentum.
c. The momentum of an object is a meaningless concept if an object is not moving, so there is no clear answer to this question.
d. The two momenta cannot be compared, because they point in different directions.
e. Their momenta are equal.
[Ques. 9] The linear momentum of a moving object is:
a. the product of its weight and its speed.
b. the product of its mass and the distance it has traveled.
c. the product of its mass times its velocity squared.
d. the product of its velocity and its mass.
e. the sum of its mass and its velocity.
[Ques. 10] A gravitational field is NOT:
a. always the same regardless of how the objects move.
b. measured in newtons.
c. a vector field.
d. a field that has both size and direction.
e. imaginary.
Quick Reply
