Gravitation Question 172
Question:The escape velocity from earth is $ [v _{es}.] $ A body is projected with velocity $ [2v _{es}] $ with what constant velocity will it move in the inter planetary space[DCE 2002]
Options:
A) $ [v _{es}] $
B) $ [3v _{es}] $
C) $ [\sqrt{3}v _{es}] $
D) $ [\sqrt{5}v _{es}] $
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Answer:
Correct Answer: C
Solution:
Velocity of body in inter planetary space
$ [v’=\sqrt{v^{2}-v _{es}^{2}}] $
where $ [v _{es}=] $ escape velocity and
v = velocity of projection $ [v’=\sqrt{{{(2v _{es})}^{2}}-v _{es}^{2}}=\sqrt{3v _{es}^{2}}] $
Þ $ [v’=\sqrt{3}\ v _{es}] $
