Gravitation Question 183
Question: A planet moves around the sun. At a given point P, it is closest from the sun at a distance $ [d_{1}] $ and has a speed $ [v_{1}] $ . At another point Q,whenit is farthest from the sun at a distance $ [d_{2}] $ , its speed will be [MP PMT 1987; DCE 2002]
Options:
A) $ [\frac{d_{1}^{2}v_{1}}{d_{2}^{2}}] $
B) $ [\frac{d_{2}v_{1}}{d_{1}}] $
C) $ [\frac{d_{1}v_{1}}{d_{2}}] $
D) $ [\frac{d_{2}^{2}v_{1}}{d_{1}^{2}}] $
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Answer:
Correct Answer: C
Solution:
Angular momentum remains constant $ [mv_{1}d_{1}=mv_{2}d_{2},\Rightarrow ,v_{2}=\frac{v_{1}d_{1}}{d_{2}}] $