Chapter 8, Problem 37A

When jumping from a significant height, why is it advantageous to land with your knees slightly bent?

To determine

The reason that it is advantageous to land with your knees slightly bent.

Answer to Problem 37A

It will reduce the impact force on the knees.

Explanation of Solution

Introduction:

Impulse delivered 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

Now, while jumping from a significant height, the change in momentum will be same. So, by bending the knees, one can increase the impact time and thereby decrease the impact force.

Conclusion:

Hence, to reduce the impact force on the knees, it is suggested to bend the knees while jumping from a height.