How much momentum will a dumb-bell of mass 10 kg transfer to the floor if it falls from a height of 80 cm? Take its downward acceleration to be 10 m s-2.
Firstly, we will calculate the final velocity:
Given,
Initial velocity, u = 0 (As it falls from rest)
Final velocity, v =?
Acceleration, a = 10 ms2
And, Distance, s = 80 cm
= m
= 0.8 m
We know that,
v2 = u2 + 2as
v2 = (0)2 + 2 × 10 × 0.8
v2 = 16
v =
= 4 m/s
Momentum = Mass × Velocity
= 10 ×4
= 40 kg m/s