The Total solution for NCERT class 6-12
How much momentum will a dumb-bell of mass 10 kg transfer to the floor ifit falls from a height of 80 cm? Take its downward acceleration to be 10 ms–2.
Given, mass of thedumb-bell (m) = 10kg
Distance covered (s) =80cm = 0.8m
Initial velocity (u) =0 (it is dropped from a position of rest)
Acceleration (a) =10ms-2
Terminal velocity (v)=?
Momentum of thedumb-bell when it hits the ground = mv
v = 4 m/s
The momentumtransferred by the dumb-bell to the floor = (10kg) × (4 m/s) = 40 kg.m.s-1