4.1 Give the magnitude and direction of the net force acting on
(a) a drop of rain falling down with a constant speed,
(b) a cork of mass 10 g floating on water,
(c) a kite skillfully held stationary in the sky,
(d) a car moving with a constant velocity of 30km/h on a rough road,
(e) a high-speed electron in space far from all material objects, and free of electric and magnetic fields.