The position of a 250g object is given (in meters) by x=5.0t^3 -8.0t^2 -44t , where t is in seconds.
a) Determine the net rate of work done on this object at t =2.1s
b) Determine the net rate of work done on this object at t =3.9s
c) What is the average net power input during the interval from t=0s to t=2.1s ?
d) What is the average net power input during the interval from t=2.1s to t=3.9s?