(b)You want to find out the power needed for a CD driver motor.
(c)A nozzle issues a jet of water with a high velocity, which impinges upon the blades of turbine. The blades deflect the jet of water through an angle. You have to find out the force exerted by the jet upon the turbine.
L1 : Fundamentals of Engineering Mechanics

Imagine the following situations:

(a) You have to design a car, which can run at a speed of 140 km/hr on an expressway. In order to do this, you have to find engine power and the forces acting on the car body. Forces will come due to wind resistance, rolling resistance and inertia.