A force of 10 N acts on a body of mass 1.0 kg at rest. Find the work done in 4 seconds.

Explanation

F = 10 N, m = 1.0 kg , u = 0, t = 4s, acceleration
`a=(F)/(m)=(10)/(1)=10 ms^(-2)`.
Its displacement `S=ut+(1)/(2)at^(2)=0+(1)/(2)(10)4^(2)=80m`
The work done W = FS = maS = `1.0xx10xx80=800J`