Question

A 0.85 kg soccer ball is booted straight up in the air. If it left the soccer player's foot at a height of 1.0 m and reaches a height of 47.0 m, what was its kinetic energy immediately after it was kicked?​

Answer 1

Answer:

383 J

Explanation:

m = 0.85 kg, h = 1.0 m, H = 47.0 m

Find KE at h

At h, total energy = KE + mgh

At H, KE = 0, total energy = mgH

Energy conservation:

KE + mgh = mgH

so KE = mgH - mgh = mg(H - h) = 0.85*9.8*(47.0-1.0) = 383 J