Question

A ball has a 8 J of kinetic energy and its mechanical energy is 25 J. If the ball has a mass of 3.2 kg, what is its height above the ground?

Answer 1

0.531m

Step-by-step explanation:

Soln

Mass = 3.2kg

Kinetic energy = 8 J

Mechanical energy = 25 J

Recall,

Mechanical energy = K.E + P.E

But P.E = mass × g × h

where g = acceleration due to gravity = 10ms² and h = height.

Mechanical energy = K.E + mass × g × h

25 = 8 + 3.2×10×h

25 - 8 = 32×h

17 = 32×h

divide both sides by 32

17/32 = h

h = 0.531 metres.