Question

A ball is dropped from the top of a cliff. By the time it reaches the ground, all of its gravitational potential energy has been transferred into kinetic energy. If the ball is travelling at 20m/s when it hits the ground, what height was it dropped from? (Assume that the gravitational field strength is 10N/kg.)

Answer 1

Answer:

20 m

Explanation:

Initial potential energy = final kinetic energy

mgh = 1/2 mv²

gh = 1/2 v²

h = v² / (2g)

Given v = 20 m/s and g = 10 m/s²:

h = (20 m/s)² / (2 × 10 m/s²)

h = 20 m