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

Explanation

(a) As the drop of rain is failing with constant speed, in accordance with first law of motion, the net force on the drop of rain is zero .
(b) As the cork is floating on water, its weight is being balanced by the upthrust (equal to weight of water dissipated ) . Hence net force on the cork is zero.
(c ) Net force on a kite skilfully held stationary in sky is zero because it is at rest.
(d) Since car is moving with a constant velocity , the net force on the car is zero.
(e) Since electron is far away from all material agencies producing electromagnetic and gravitational forces, the net force on electron is zero.