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

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17 March, 08:24

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Alfonso Foley · Answer 1

20 meters.

Explanation:

mgh = 1/2mv^2

gh = 1/2v^2

10 (h) = 1/2 (20) ^2

10h = 1/2 (400)

10h = 200

(10h) / 10 = 200/10

h = 20