Question

42
The mass of a bucket full of water is 15 kg. It
being pulled up from a 15m deep well. Due to
hole in the bucket 6 kg water flows out of the bucket
The work done in drawing the bucket out of the wel.
will be (g = 10m/s)
(1) 900 J
(2) 1500 J
371800 J
(4) 2100 J​

Answer 1

Answer:

Explanation:

Mass varies from deep of well to 15 m in height .

let ¢ (cent/s) is mass per unit height .  

so,  

dm  = ¢dx  

      =  6/15dx  

M =  m-dm

now,  

workdone = change in potential energy  

= F*x

= ( m -dm)g * x

= mgx -dm*gx  

= 15 * 10 * 15 -6/15 gx.dx

=2250 - 6/15 * 10 * 225/2  

=2250 -  3 * 15 * 10

= 2250 - 450

= 1800 Joule (Ans.)