A 5 kg rock is dropped over the edge of a 15 m cliff. What is the momentum of the rock as it strikes the ground

Momentum of the rock = 85.7 Kgm/s

Explanation:

Given

Rock weight = 5 kg

height of a cliff = 15 m

find Momentum = ?

Momentum = mass * velocity

we don't have velocity here so let's find the velocity v

Potential energy of the rock will be = mgh

P. E. = mgh

⇒ 5 * 9.8 * 15

⇒ 735 J

The Kinetic energy before a moment of touching the ground will be = maximum potential energy = 735 J ⇒ Going by the law of conservation law.

K. E. = 1/2 m * v²

735 = 1/2 * 5 * v²

v² = 294

v = 17.14 m/s

Now get on to the momentum

Momentum = m * v

Momentum = 5 * 17.14

Momentum = 85.7 Kgm/s

The Momentum of the rock as it strikes ground will be 85.7 Kgm/s.