Question

A man drops a 10 kg rock from the top of a 5 m ladder. What is its speed just before it hits the ground?
What is its kinetic energy when it reaches the ground ? (g = 10 m/s)​

Answer 1

Given:-

• A man drops a 10 kg rock from the top of a 5 m ladder.

To Find:-

• Kinetic energy of rock when it reaches ground.

Solution:-

By work energy theorem

W = Δ K. E.

⇛W gravity = K. Efinal - Einital

⇛mgh = 1/2 mv² - 0

Put the given values

⇛1/2 mv² = 10 × 10 × 5

⇛KE final = 500 J

Hence ,

Kinetic energy of rock when it reaches ground is 500 J.

Answer 2

A man drops a 10 kg rock from the top of a 5 m ladder. What is its speed just before it hits the ground?

What is its kinetic energy when it reaches the ground ? (g = 10 m/s)