Question

Please help :)

Kevin drops a 75 g “bouncy ball” out his second floor window, which is 8.0 m above the hard ground (pavement). He noticed that the ball bounced back up to a height of 6.1 m above the ground.

a) How much kinetic energy did the ball have just after it hit the ground (and bounced up again).

Answer 1

KE = 1/2mv^2

1. Find velocity:
8.0 + 6.1 = 14.1 m/s

2. Plug and Chug
KE = 1/2mv^2
KE = 1/2(75g)(14.1 m/s)^2
KE = 7,455.375 Joules