A large stone is dragged 15m over a frozen lake. If the coefficient of friction between the stone and the ice is 0.1 and the whole process takes 8 seconds, how much work is done and how much power is required?
Work required = (Friction Force)*(Distance)
= (0.01)*M*g
Divide that by the 8 s time interval for the power. You are going to have to know the value of M to get a numeric result. You have not said what it is, only thet it is "Large".