Gravitation Question 336
Question: The potential energy of a rock, having mass m and rotating at a height of$ [3.2\times 10^{6}m] $ from the earth surface, is
Options:
A) $ [-6,,mgR_{e}] $
B) $ [-0.67,,mgR_{e}] $
C) $ [-0.99,,mgR_{e}] $
D) $ [-0.33,,mgR_{e}] $
Show Answer
Answer:
Correct Answer: B
Solution:
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Mass of the $ [rock=m] $ and height of rock from earth $ [\left( h \right)= R_{e}/2 =3.2\times 10^{6}m] $
We know that gravitational potential energy of the rock rotating at height
$ [h=-\frac{GM_{e}m}{{R_{e}}+h}=-\frac{2}{3}mgR_{e}] $
$ [\left( where, GM_{e}= gR_{e}^{2} and h = R_{e} \right)] $
