Question

A raindrop has a mass of 5.4 × 10-7 kg and is falling near the surface of the earth. Calculate the magnitude of the gravitational force exerted (a) on the raindrop by the earth and (b) on the earth by the raindrop.

Answer 1

Answer:

(a) 5.29 x 10^-6 N

(b) 5.29 x 10^-6 N

Explanation:

mass of rain drop, m = 5.4 x 10^-7 kg

acceleration due to gravity, g = 9.8 m/s^2

The force of gravitation is defined as the force with which the earth exerts on the body towards its centre.

(a) Force on rain drop by the earth = mass of rain drop x gravity

F = 5.4 x 10^-7 x 9.8 = 5.29 x 10^-6 N

(b) The force of earth by the raindrop is same as the force on raindrop by the earth.

F = 5.29 x 10^-6 N

Answer 2

Answer

given,

mass of raindrop = 5.4 × 10⁻⁷ kg

acceleration due to gravity = 9.8 m/s²

a) magnitude of gravitational force on the rain drop

   Force on the rain drop = m g

   Force on the rain drop = 5.4 × 10⁻⁷ x  9.8

                                          = 5.292 x 10⁻⁶ N

Hence, force on raindrop by earth is equal to 5.292 x 10⁻⁶ N

b) by newtons third law

    Force by the earth on the raindrop will be opposite to the force by raindrop on earth.

Force on earth by raindrop = - 5.292 x 10⁻⁶ N

  negative sign represent that force is acting in the opposite direction.