Suppose we have a trolley currently at rest at point A, but the motor switches on, so that it accelerates and reaches point B, at point B, the velocity is 5m/s, Distance of A-B is 10m, mass of the trolley is 12kg, find the power required.
I attempt to work out like this:
Assume: a=acceleration, F=force acting on the trolley, m=mass, u=initial velocity, v=final velocity, s=distance traveled, t=total time needed to travel from A to B, P=power required
Therefore, P=F(s/t) =m(a)(s/t)
also, v^2-u^2=2(a)(s) a=(v^2-u^2)/(2s) =(5^2-0)/(2x10) =1.25
find t: v=u+at t=(v-u)/a =(5-0)/1.25 =4
Therefore, P=12(1.25)(10/4) =37.5W
so power is 37.5W, is this correct?