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 \( 10 m/s^2\).

Given, mass of the dumb-bell (m) = 10 kg

Distance covered (s) = 80 cm = 0.8 m

Initial velocity (u) = 0

Acceleration (a) = \( 10 m/s^2 \)

Momentum of the dumb-bell when it hits the ground = m v

We know that, \( v^2 - u^2 = 2 a s \ \)
\( \Rightarrow \ v^2 - 0 = 2(10)(0.8) \ \)
\( \Rightarrow \ v = 4 \)

The momentum transferred by the dumb-bell to the floor = (10) × (4) = 40 kg m/s