Gravitation - Result Question 10
10. Two spherical bodies of mass $M$ and $5 M$ and radii $R$ and $2 R$ released in free space with initial separation between their centres equal to 12 $R$. If they attract each other due to gravitational force only, then the distance covered by the smaller body before collision is
(a) $4.5 R$
(b) $7.5 R$
(c) $1.5 R$
(d) $2.5 R$
[2015]
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Answer:
Correct Answer: 10. (b)
Solution:
- (b) Let the distance moved by spherical body of mass M is $x_1$ and by spherical body of mass $5 m$ is $x_2$
Before collision At the time of collision
As their C.M. will remain stationary
So, $(M)(x_1)=(5 M)(x_2)$ or, $x_1=5 x_2$
$x_1+x_2=9 R$
So, $x_1=7.5 R$
