Question

A particle of mass 2 kg falls from height of 20 cm on a concrete floor and comes to rest after striking it. What is the momentum that is transferred to the floor?

Answer 1

Answer:

4 kgm/s

Explanation:

Given,

A particle of mass 2 kg falls from height of 20 cm on a concrete floor and comes to rest after striking it.

First let us find the momentum of the particle when it hits the concrete floor.

p = mv

p = m√2gh

p = 2√2(10)(20×10^-2)

p = 2√4

p = 4 kgm/s

By the conservation of angular momentum,

Initial momentum before collision = Final momentum after collision

pi(particle) + pi(surface) = pf(particle) + pf(surface)

4 + 0 = 0 + pf(surface)

pf(surface) = 4 kgm/s

Hence, momentum transferred to the surface = 4 kgm/s