A hole is drilled half way to the centre of the earth. A body weighs 300 N on the surface of the earth. How much will, it weigh at the bottom of the hole?

Step-by-step solution

Given, distance of bottom of hole from the surface of earth (d) = half the radius of earth = R e 2 If g be the value of gravitational acceleration on the surface of earth, then weight of body m g = 300 N If g’ be the gravitational acceleration at the bottom of hole, then g ' = g 1 - d R e = g 1 - R e 2 R e ⇒ g ' = g 2 ∴ Weight of the body on the bottom of hole, m g ' = m g 2 = 300 2 = 150 N