Question:
A particle is initially traveling to the right when it hits a wall and turns around to the left. The momentum after the collision is less than the initial momentum.
a-the impulse on the particle is to the right
b-the impulse on the particle is to the left
c-there is no impulse on the particle
d-none of the above
Question: When a particle hits the ground and comes to rest, the direction of the total impulse is
a-up
b-down
c-the total impulse is zero, as the particle stops
d-none of the above
b-the impulse on the particle is to the left
c-the total impulse is zero, as the particle stops
b
a
To determine the impulse on a particle after a collision or when it comes to rest, we need to consider the conservation of momentum and the direction of the change in momentum.
In the first question, the particle initially travels to the right and then changes direction to the left after hitting the wall. The momentum of the particle changes from a positive value to a negative value, indicating a change in direction. Since the momentum decreases, we can conclude that the impulse on the particle is in the opposite direction of its initial motion. Therefore, the correct answer is b) the impulse on the particle is to the left.
In the second question, when a particle hits the ground and comes to rest, its momentum changes from a non-zero value to zero. This change in momentum indicates a decrease in magnitude but not necessarily a change in direction. Since the particle is brought to rest, the impulse on the particle is in the direction opposite to its initial motion. Therefore, the correct answer is b) down.
Remember, impulse is defined as the change in momentum, and the direction of the change in momentum determines the direction of the impulse.