Chapter 8, Problem 36A

To determine

The reason that the gymnasts use floor mats that are very thick.

Answer to Problem 36A

It is done to increase the impact time and thereby to reduce the impact force.

Explanation of Solution

Introduction:

Impulse on an object is given by,

  $F\Delta t=\Delta p$

Where,

  $F=$ force exerted on an object

  $\Delta t=$ time taken to change its momentum

  $\Delta p=$ change in momentum of the object

In case of falling, the change in momentum of the gymnast will be same. Thus, to reduce the impact force on gymnast, the impact time has to be increased. Due to this reason, the gymnasts use floor mats that are very thick so that it will takes time to change the momentum.

Conclusion:

Hence, the thick mats increase the impact time of the change in momentum of the gymnasts due to which the impact force on them decreases.