A scooter moves with a speed of $$7 \mathrm{~ms}^{-1}$$, on a straight road and is stopped by applying the brakes. Before stopping, the scooter travels $$10 \mathrm{~m}$$. If the weight of the scooter is $$\mathrm{W}$$, then the total resistance to the motion of the scooter will be

When water falls from a height of $$80 \mathrm{~m}$$ at the rate of $$20 \mathrm{~kg} \mathrm{~s}^{-1}$$ to operate a turbine the losses due to frictional force are $$20 \%$$ of input energy. How much power is generated by the turbine?

An electric motor raises a mass of $$1.5 \mathrm{~kg}$$, a distance of $$1.128 \mathrm{~m}$$ in time of $$4.79 \mathrm{~s}$$. Calculate the power to an appropriate significant figures. (take $$g=9.81 \mathrm{~ms}^{-2}$$)