Question
A body of mass 32kg is suspended by a spring balance from the roof of a vertically operating lift going downward from rest . At that instant the lift covered 20m and 50m , the spring balance showed 30 kg & 36 kg respt. the vel. is increasing at 20m & decreasing at 50m. Plzz sir explain this.
Joshi sir comment
for downward journey
first case
32g-30g = 2g = 32a so a = g/16
second case
32g-36g = -4g = 32a so a = -g/8
so it is acceleration upto 20 m and retardation after that