If the pole-vaulter were to land on concrete rather than on a cushion, the impulse that stops the fall would be what?
A) Greater because of the rigidity of the concrete.
B) Greater because of the force of impact is greater.
C) The same because impulse is the change in momentum of the object.
D) Less, because he would come to a stop over a shorter period of time.
E) Less, because there is less change in momentum during the stop.
the same bc impulse is the change in momentum of the object.
The correct answer is D) Less, because he would come to a stop over a shorter period of time.
When the pole-vaulter lands on a cushion, the cushion provides a longer duration of contact for the body to come to a stop. This longer duration reduces the force of impact and, subsequently, the impulse required to stop the fall.
On the other hand, if the pole-vaulter were to land on concrete, the time of contact would be much shorter. With a shorter contact time, the body would experience a larger force of impact, requiring a larger impulse to stop the fall. Therefore, the impulse that stops the fall would be less if the pole-vaulter were to land on concrete rather than on a cushion.
To answer this question, we need to understand the concept of impulse and its relationship with momentum. Impulse is defined as the change in momentum of an object.
Momentum is the product of an object's mass and its velocity. It represents the object's tendency to keep moving in its current direction.
When the pole-vaulter lands, the impulse that stops their fall is equal to the change in momentum they experience. If the pole-vaulter were to land on concrete instead of a cushion, we can consider two scenarios:
Scenario 1: Landing on concrete
In this case, the pole-vaulter would come to a stop over a shorter period of time compared to landing on a cushion. The rigid surface of concrete would provide less cushioning, resulting in a quicker deceleration. As a result, the change in momentum during the stop would be smaller.
Scenario 2: Landing on a cushion
In this case, the pole-vaulter would experience a longer duration of impact, as the cushion provides some deformation and allows for a slower deceleration. The longer duration reduces the force of impact and allows for more time to come to a stop. Therefore, the change in momentum during the stop would be greater.
From the above analysis, we can conclude that the correct answer is:
E) Less, because there is less change in momentum during the stop