Question

What is the power output in watts and horsepower of a 70.0-kg sprinter who accelerates from rest to 10.0 m/s in 3.00 s

Answer 1

Given that,

Mass of a sprinter = 70 kg

Initial velocity, u = 0

Final velocity, v = 10 m/s

Time, t = 3 s

To find,

Power output.

Solution,

The work done by the sprinter is equal to its kinetic energy.

`W=(1)/(2)m(v^2-u^2)\\\\=(1)/(2)* 70* 10^2\\\\=3500\ J`

Let P is power output. Power is equal to work done per unit time. So,

`P=(3500\ J)/(3\ s)\\\\=1166.67\ W`

So, the power output is 1166.66 W.