A body of mass `32 kg` is suspended by a spring balance from the roof of vertically operating lift and going downwards from rest. At the instant the lift has covered 20 m and 50 m, the spiring balance showed 30 kg and 36 kg respectively. The velocity of the lift is

Options

A. decreasing at 20 m and increasing at 50 m
B. increasing at 20 m and decreasing at 50 m
C. continuously increasing at constant rate throughtout the journey
D. remaing constant throught the journey

Answer

B

Explanation

N= m(g-a) ,N lt mg if a `(darr)`
and Ngt mg if a `(uarr)`
Reading of spring balance is than m
if a `(darr)` and reading of spring balance is greater then m if a `(uarr)`