Question

I need a bit of help on this one, can anyone answer?

Answer 1

Potential energy = m · g · h

-- When you held the ball at 2.0 meters above the floor, it had

(0.5 kg) · (9.8 m/s²) · (2.0 m) = 9.8 Joules of potential energy.

-- After it bounced and went back up as high as it could, it was only 1.8 meters above the floor.  Its potential energy was

(0.5 kg) · (9.8 m/s²) · (1.8 m) = 8.82 Joules

-- Between the drop and the top of the bounce, it lost

(9.8 - 8.82) = 0.98 Joule .

-- The energy was lost when the ball hit the floor.  During the hit, 0.98 joule of kinetic energy turned to thermal energy, which slightly heated the ball and the floor.