Question

A pebble of mass 0.05 kg is thrown vertically upwards. Give the direction and magnitude of the net force on the pebble,
(a) during its upward motion,
(b) during its downward motion,
(c) at the highest point where it is momentarily at rest. Do your answers change if the pebble was thrown at an angle of 45° with the horizontal direction?
Ignore air resistance.
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Answer 1

Explanation:

(a) As the rain drop is flling with a constant speed, its accleration, a = 0. Hence net force F= ma = 0.

(b) As the cork is floating on water, its weight is balanced by the upthrust due to water. Therefore, the net force on the cork is 0.

(c) As the kite is held stationery, in accordance with the first law of motion, the net force on the kite is 0.

(d) Force is being applied to overcome the force of friction. But as velocity of the car is constant, its accleleration, a = 0. Hence net force on the car F = ma = 0.

(e) As the high speed electron in space is far away from all gravitating objects and free of electric and magnetic fields, the net force on electron is 0.

Answer 2

Explanation:

Answer refer in Attachment

Thank you