Question 6.20:

A body of mass 0.5 kg travels in a straight line with velocity v = ax3/2 where a = 5m-1/2 s-1. What is the work done by the net force during its displacement from x = 0 to x = 2 m?

Mass of the body, m = 0.5 kg

Velocity of the body is governed by the equation, v = ax3/2 with a = 5 m-1/2 s-1

Initial velocity, u (at x = 0) = 0

Final velocity v (at x = 2 m) = 102 m/s

Work done, W = Change in kinetic energy

= 12mv2 - u2
= 12 × 0.51022 - 02
= 12 × 0.5 × 10 ×10 ×2 = 50 J