Answer:
Second choice
Explanation:
I suppose ME is the same as POTENTIAL energy
ME = mgh = 70 * 10 * 12 = 8400j
Half way down, 4200 j is converted to Kinetic Energy
1/2 m v^2 = 4200
1/2 (70) v^2 = 4200 v = 10.95 m/s
Just before impact ALL of the 8400 j is now KE
1/2 (70)v^2 = 8400 v = 15.49 m/s
