Question

A 6.0 kg rock falls from a cliff and hits the ground at 32.5 m/s. a) Determine the kinetic energy. b) How much potential energy did it have before it fell? C) How much mechanical energy does it have before it hits the floor? Please answer all three.

Answer 1

Answer:

See below

Explanation:

KE = 1/2 m v^2 =   1/2 *6 * 32.5^2 =  3168.75 j

PE = mgh  = KE at end = 3168.75 j  

ME = 3168.75 j      

ME is  KE + PE at any point

   before it falls it has no KE     before it hits it has no PE

      so ME = 3168.75 j