A body of mass 500 g is moving with a speed 10 `ms^(-1)` . A force acts on it which makes it to move with a speed 20 `ms^(-1)` . Find : (i) the change in kinetic energy of the body, and (ii) the work done by the force on the body.

Explanation

Given, `m=500g=0.5kg,u=10ms^(-1),v=20ms^(-1)`
(i) Increase in kinetic energy `=1/2m(v^2-u^2)`
`=1/2xx0.5xx[(20)^2-(10)^2]=75J`
(ii) Work done by the force = increase in kinetic energy = 75J