Question

Two girls of same mass run up a stair case in 10s and 15s respectively. The ratio of the powers developed by them

Answer 1

Answer:

Given:

2 girls run up a stair case in 10s and 15s.

To find:

Ratio of powers developed by the girls

Concept:

Power is defined as the instantaneous rate of doing work. In other words , it's the ratio of work done to the time taken ;

$\boxed{ \bold{power = \dfrac{work}{time} }}$

In this question, both the girls have done the same work against gravitational force by running up equal number of staircase.

But since the time in which the ran up is different, we can say that the power generated by them is different.

Calculation:

By 1st girl :

$\bold{power = \dfrac{work}{time} }$

$= > \bold{power = \dfrac{m \times g \times h}{10} }$

$= > \bold{power = \dfrac{mgh}{10} } \: \: .....(1)$

By 2nd girl :

$\bold{power = \dfrac{work}{time} }$

$= > \bold{power = \dfrac{mgh}{15} } \: \: .....(2)$

So ratio will be :

$ratio = \dfrac{mgh}{10} \: : \: \dfrac{mgh}{15}$

$= > ratio = 3 \: : \: 2$

Final answer :

$\boxed{ \red{ \bold{ \huge{ ratio = 3 \: : \: 2}}}}$

Answer 2

$</p><p>\tt{\purple{\huge{Hello!!! }}}$

$</p><p>\tt{\red{Given \: - }}$

• Two girls of same mass run up a stair case in 10s and 15s respectively.

$</p><p>\tt{\orange{Step-By-Step-Explaination \: - }}$

$</p><p>\tt{\blue{Girl \: 1 }}$

$</p><p>\tt{\purple{Power = \dfrac{mgh}{10}}}$

$</p><p></p><p>\tt{\blue{Girl \: 2 }}$

$</p><p>\tt{\purple{Power = \dfrac{mgh}{15}}}$

Ratio : 3:2