(a) Define the term ‘average power’.

(b) When a player hits a football, it moves along the curved path and then falls to the ground, Calculate the work done by the force of gravity on the football.

© Two friends Ram and Shyam, each having zveight of 40 kg, go for rock climbing. Ram climbs to a height of 3 m in 10 s and Shyam covers the same height in 12 s. Is the work done by Ram and Shyam equal or not ? Compare the power of Ram and Shyam.

(a) Average power is defined as the ratio of total work done to the total time taken.

(b) When a player hits a football, it moves along the curved path and then falls to the ground, then work done by the force of gravity

W = mgh.

Since h = 0, therefore, W = 0

© Work done by Ram and Shyam is same because both have same weight and both climb equal height.

Power of Ram = PE / t = 40 x 9.8 x 3 /10

= 117.6 W

Power of Shyam = PE / t = 40 x 9.8 x 3/12

= 98 W

Power of Ram > Power of Shyam