A man pulls a bucket of water from a well of depth H. if the mass of uniform rope and bucket full of water are m and M respectively. The value of work done by man is
A.(M+m/2).g.h
B.(M+m)gh
C.(m+M)/2.G.H
D. none
utkarsh0110 and cherry.berry has given absolutely correct answer. So, you can refer to their answers.
Here in the answer work done is computed using the fact that work done is equal to the change in potential energy. The work done in lifting the mass M of the bucket to the height H is MgH. In the case of the rope, first center of mass of the rope is being calculated which is at the depth H/2 from the top of the well as mass is uniformly distributed along its whole length. Second, the change in potential energy has been computed which is from the depth of the center of the mass of the rope i.e. mgH/2. Therefore, work done in lifting the whole system is
Answer is (A)
@utkarsh0110 and cherry.berry. Good answer. You both get thumb up. Keep posting!!