The relation between the displacement x and the time t for a body of mass 2kg moving under the action of force is given by x=t3/3 , where x is in metre and t in second , calculate the work done by body in first 2 seconds.
Here,
Mass, m = 2 kg
Displacement is given as, x = t3/3
So, d(x)/dt = (3)(t2)/3 = t2
=> d2(x)/dt2 = 2t
=> a = 2t
This is the acceleration of the body.
Now,
For a small displacement ‘dx’ the work done is,
dW = F.dx
=> dW = (ma).d(t3/3)
=> dW = 2(2t)(3t2/3)
=> dW = 4t3