Question

Two girls,each of weight 400N climb up a rope through a height of 8mt. We name one of the girls A and another B. Girl A takes 20s while B takes 50s to accomplish this takes. What is the power expended by each girl

Answer 1

here is your answer..

Answer 2

Answer:

Explanation:

Power expended by girl A:

Weight of the girl, mg = 400 N

Displacement (height), h = 8 m

Time taken, t = 20 s

We know,

$\sf{}Power, P = \dfrac{Work\ done}{Time\ taken}$

So,

$\sf{}:\implies \dfrac{mgh}{t}:$

$\sf{}:\implies \dfrac{400\times 8m}{20s}:$

$\sf{}\therefore 160w$

Power expended by girl A is 160 W.

(ii) Power expended by girl B:

Weight of the girl, mg = 400 N

Displacement (height), h = 8 m

Time taken, t = 50 s

So,

$\sf{}:\implies \dfrac{mgh}{t}:$

$\sf{}:\implies \dfrac{400\times 8m}{50s}:$

$\sf{}\therefore 64W$

Power expended by girl B is 64 W.