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.

note: the given question is incomplete.

complete question is given below.

which is an example of kinetic energy?

a. the energy stored in ethanol  

b. a hockey puck sliding across the ice  

c. a compressed spring  

d. a ball sitting at the top of a ramp

solution: the kinetic energy is the energy posses by the virtue of the motion of the object.

in the given options, a, c and d are the example of potential energy because it is the energy posses by the virtue of the rest of the object. but option b has the kinetic energy as the object is in motion.

hence, a hockey puck sliding across the ice   is the apex example of kinetic energy.

so, the option (b) a hockey puck sliding across the ice   is the correct option.