Question

An athlete is working out in the weight room. He steadily holds 50 kilograms above his head for 10 seconds. Which statement is true about this situation? A. The athlete isn't doing any work because he doesn't move the weight. B. The athlete isn't doing any work because he doesn't hold the weight long enough. C. The athlete is doing work because he prevents the weight from falling downward. D. The athlete is doing work because 50 kilograms is a significant load to lift.

Answer 1

A. The athlete isn't doing any work because he doesn't move the weight.

Step-by-step explanation:

As we know that work done is defined as the product of force and displacement of the object in the direction of the force

so here we can say

`W = F d cos\theta`

now we know that here force is applied by the athlete to hold the mass but the mass is steady at its position

The mass is not moving so we can say that

`d = 0`

so the work done by the athlete will be zero

so correct answer is

A. The athlete isn't doing any work because he doesn't move the weight.