Question 1: A 1 kg laboratory cart moving with a velocity of 0.5 m/s due east collides with and sticks to a similar cart

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Question 1: A 1 kg laboratory cart moving with
a velocity of 0.5 m/s due east collides with and sticks to a
similar cart initially at rest. After the collision, the two carts
move off together with a velocity of 0.25 m/s due east. The total
momentum of this frictionless system is
A. greater before the collision than after the collision
B. zero after the collision
C. the same before and after the collision
D. zero before the collision
Question 2: Which situation will produce
the greatest change of momentum for a 1.0-kilogram cart?
A. accelerating it from 2.0 m/s to 4.0 m/s
B. applying a net force of 5.0 N for 2.0 s
C. applying a net force of 10.0 N for 0.5 s
D. accelerating it from rest to 3.0 m/s