Question

A body is taken to depth of 64 Km from the surface of earth. What is the percentage decrease in value of g..?
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Answer 1

Explanation:

gd = Gravity at the depth of 64 km

g = Gravity at the surface of the Earth

d = 64 km

r = radius of Earth = 6400000 km

$gd = g(1 - \frac{d}{r})$

$gd = 9.8(1 - \frac{20}{6400000} )$

$gd = 9.8(1 - \frac{1}{320000})$

$gd = 9.79 \: m {s}^{ - 2}$

Percentage decrease

$\frac{(9.8 - 9.79)}{9.8} \times 100 = 0.1\%$

Therefore, it is your answer.

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