Question

Escape velocity of a body of 1 kg mass on a planet is 100 m/sec. Gravitational Potential energy of the body at the Planet is

• A. – 5000 J
• B. – 1000 J
• C. – 2400 J
• D. 5000 J

Answer 1

Answer: (A)

– 5000 J

Answer 2

$v _ { e } = \sqrt { \frac { 2 G M } { R } } = 100 \Rightarrow \frac { G M } { R } = 5000$

Potential energy $U = - \frac { G M m } { R } = - 5000 \mathrm {~J}$