NEET2020Physics-Gravitation
NEET 2020 Physics Variation of g with Height MCQ Question
Type: MCQ-numerical-Easy-Class 11
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 ?
A
30 N
B
24 N
C
48 N
D
32 N
Correct Answer
Option D
Detailed Explanation
At height h above the Earth's surface, gravitational force F = mg × [R/(R+h)]². At h = R/2: F = 72 × [R/(R + R/2)]² = 72 × [R/(3R/2)]² = 72 × (2/3)² = 72 × 4/9 = 32 N. The correct answer is D (32 N). The original explanation made an arithmetic error getting 24 N instead of 32 N.
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