A body weighs 72 N on the surface of the earth. What is the gravitational force on it, at a height equal to half the radius of the earth ?

1. 48 N

2. 32 N

3. 30 N

4. 24 N

Doubtly Asked 30 Oct 2026 NEET UG 2020 Practice test neet Save WhatsApp Report

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Answer: 2. 32 N

Gravitational force varies as $g$, and $g$ at height $h$ is $g\left(\dfrac{R}{R+h}\right)^2$.

With $h=R/2$: $\left(\dfrac{R}{1.5R}\right)^2=\dfrac49$.

$$F=72\times\frac49=32\ \text{N}$$

Answer: option 2.

Doubtly AI · 30 Oct 2026 AI-generated · not yet verified Report

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