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>> $An object is propelled vertically to a m$

Question

An object is propelled vertically to a maximum height of 4R from the surface of a planet of radius R and mass M. The speed of object when it returns to the surface of the planet is.

A

$2 \frac{2 G M}{5 R}$

B

$\frac{G M}{2 R}$

C

$\frac{3 G M}{2 R}$

D

$\frac{G M}{5 R}$

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Updated on : 2022-09-05

Solution

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Correct option is A)

Using Energy conservation
$\frac{- G M n}{5 R} + 0 = \frac{- G M m}{R} + \frac{1}{2} m v^{2}$
$V = 2 \frac{2 G M}{5 R}$

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The value of $n$ is

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