9. Exercises

A parachutist is falling vertically at a constant speed. He has mass 80 kg. Find the magnitude of the upward force acting on the parachute.

Each of the bodies shown below are moving with a constant velocity. Use this to find P and Q.

A bicycle moves with a constant velocity along a straight horizontal road. If the forward force which the cyclist exerts by pedalling is 28 N, what is the magnitude of the resistive force acting on the bicycle and cyclist ?

A block, of mass 4 kg, is being dragged across a rough horizontal surface at a constant velocity by a force of 20 N acting parallel to the surface. Find the coefficient of friction between the object and the surface.

A skier of mass 60 kg is travelling at a constant speed down a slope inclined 20 to the horizontal, subject to; air resistance and friction where the coefficient of friction between skier and the slope is 0.05. Find the magnitude of the air resistance force acting on the skier.

A car of mass 1600 kg is towed up a hill of inclined at 5 to the horizontal. The car moves with a constant velocity. The tow rope is at an angle of 7 to the hill.

Model the car as a particle.

a) Find the magnitude of the tension in the rope.

b) Find the magnitude of the normal reaction between the hill and the sledge.