If a 2 kg object is constantly accelerated from 0m/s to 15 m/s over 12s, how much power musy be applied at t= 3 ?

1 Answer
Apr 23, 2017

9.4W

Explanation:

Constant acceleration here denotes a constant force F.

To find out the power P required, we need to find out (dW)/(dt) , the rate of work done with respect to time at t=3s. Alternatively, the equation P=Fv can be used.

P=(dW)/(dt)=(d(Fx))/(dt)=F((dx)/(dt))=Fv=mav

To find a , we can use the kinematics equation a=(v-u)/t.

a=(15-0)/12=1.25m/s^2

To find v at t=3s , we can use v=u+at.

v=0+(1.25)(3)=3.75m/s

Therefore, the power required is

P =mav =(2)(1.25)(3.75) =9.375 =9.4W