Answer: 686 joules
Explanation:
Work done = ?
Mass of fallen object = 10 kg
Height = (12m - 5m) = 7metres
(The height is 7metres because the object fell from an height of 12m to 5m)
Acceleration due to gravity g = 9.8m/s2
Workdone = Mass x Acceleration due to gravity x height
= 10kg x 9.8m/s2 x 7 metres
= 686 joules
Thus, the work done by gravity is 686 joules
