If a runner exerts 350 J of work to make 175 W of power, then how long did it take the runner to do the work?
A. 2 sec
B. .5 sec
C. 4 sec
D. .25sec

If a runner exerts 350 J of work to generate 175 W of power, it took the runner 2 seconds to do the work.

Explanation:

Power is defined as the speed with which a job is done. In other words, power is a given amount of work done in a given unit of time. That is, it is the amount of work per unit of time that some object or system produces.

Its expression is:

where:

In this case:

Replacing:

and solving you get:

t= 2 s

If a runner exerts 350 J of work to generate 175 W of power, it took the runner 2 seconds to do the work.

the duration of a photographic flash is related to an rc time constant, which is 0.100 μs for a certain camera.