Gravitation Question 8
Question 8 - 2024 (30 Jan Shift 2)
Escape velocity of a body from earth is $11.2 km / s$. If the radius of a planet be one-third the radius of earth and mass be one-sixth that of earth, the escape velocity from the plate is:
(1) $11.2 km / s$
(2) $8.4 km / s$
(3) $4.2 km / s$
(4) $7.9 km / s$
Show Answer
Answer: (4)
Solution:
$R _P=\frac{R _E}{3}, M _P=\frac{M _E}{6}$
$V _e=\sqrt{\frac{2 GM _e}{R _e}}$
$V _P=\sqrt{\frac{2 GM _P}{R _P}}$
$\frac{V _e}{V _p}=\sqrt{2}$
$V _P=\frac{V _e}{\sqrt{2}}=\frac{11.2}{\sqrt{2}}=7.9 km / sec$
