Question

A boy takes 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 ? Take density of water = 103 kg m-3 and
g = 9.8 N kg​

Answer 1

Answer:

i. 1:1

ii. 2:3

Explanation:

P=mgh/t

P developed by son÷Power developed by father

= 2/3

Not considering units as its a ratio

W son = 20×10×20 = 4000

W father = 4000 as well ( same formula )

4000/4000 = 1