Question

3 Two persons do the same amount of work in 10 s and 20 s, respectively. What is the ratio of the power used by the first person to that by the second person?​

Answer 1

Here is your answer, Hope it helps!! :)

Answer 2

Time of person 1 = 10 s

Time of person 2 = 20 s

Work done = Same amount

We know

${\boxed{\bf Power=\dfrac{Work\;done}{Time}}}$

$\sf \longmapsto \dfrac{P1}{P2}=\dfrac{\dfrac{w}{10}}{\dfrac{w}{20}}$

$\sf\longmapsto \dfrac{P1}{P2}=\dfrac{w}{10}\times\dfrac{20}{w}$

$\sf\longmapsto \dfrac{P1}{P2}=\dfrac{\cancel{w}}{10}\times\dfrac{20}{\cancel{w}}$

$\sf\longmapsto \dfrac{P1}{P2}=\dfrac{20}{10}$

$\sf\longmapsto \dfrac{P1}{P2}=\dfrac{2}{1}$

$\sf\longmapsto P1:P2=2:1$