A. Since, the drop of rain is falling down with constant speed, the rate of change of velocity i.e. acceleration is zero. Thus, according to the Newton’s second law of motion, the force is zero.

Hence, the net force on a drop of rain falling down with a constant speed is zero.

B. There are two equal and opposite forces acting the cork floating on water. The force due to gravity i.e. weight of the cork is acting in the downward direction which is balanced by the buoyant force acting in the upward direction in the water.

Hence, the net force acting on the floating cork is zero.

C. No net force is acting on the kite held stationary in the sky. It is not executing any kind of motion at all. Thus, according to the first law of motion, it will continue to be in rest until any external force starts acting on it.

Hence, the net force acting on the kite is zero.

D. The car is moving with a constant velocity of 30km/h, the rate of change of velocity i.e. acceleration is zero. Thus, according to the Newton’s second law of motion, the force is zero.

Hence, the net force on the car moving with a constant velocity is zero.

E. There is no electric, magnetic field acting on the high-speed electron and since it is far away in space from all the material objects the gravitational field is also zero.

Thus, according to the Newton’s first law of motion, the net force acting on the high- speed electron is zero.