Question

A boy take 3 minutes to lift a 20 litre water bucket from a 20 m deep well while his father does it in 2 minutes.(a) compare:(i)the work and (ii)power developed by them.(b) How much work each does?

Answer 1

Hey!

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Volume of water = 20 l = 20/1000= 0.02 m^3

Mass of water = Density × Volume = 10^3×0.02 = 20 kg

(i) Work done by boy = mgh = 20×9.8×20 = 3920J
Work done by father = mgh = 20×9.8×20=3920J

Compare work done =>

3920 : 3920
= 1:1


(ii) Time taken by boy = 3 min = 180 s
Time taken by father = 2 min = 120 s

Power developed by the boy = Work done /Time = 3920/180

Power developed by the father = Work done /Time = 3920/120

Comparing power devolped =>

3920/180 : 3920/120
=2:3


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Hope it helps...!!!

Answer 2

Answer:

Explain

Answer is (a)(i) work 1:1

(ii) 2:3

(b) work done by each =3•92KJ

Can't explain sorry