Gravitation Question 10

Question 10 - 2024 (31 Jan Shift 2)

The mass of the moon is $1 / 144$ times the mass of a planet and its diameter $1 / 16$ times the diameter of a planet. If the escape velocity on the planet is $v$, the escape velocity on the moon will be:

(1) $\frac{v}{3}$

(2) $\frac{v}{4}$

(3) $\frac{v}{12}$

(4) $\frac{v}{6}$

Show Answer

Answer: (1)

Solution:

$V _{\text {escape }}=\sqrt{\frac{2 GM}{R}}$

$V _{\text {planet }}=\sqrt{\frac{2 GM}{R}}=V$

$V _{\text {Moon }}=\sqrt{\frac{2 GM \times 16}{144 R}}=\frac{1}{3} \sqrt{\frac{2 GM}{R}}$

$V _{\text {Moon }}=\frac{V _{\text {Planet }}}{3}=\frac{V}{3}$