Potential energy of a satellite having mass ‘m’ and rotating... | PHYSICS - GRAVITATIONAL POTENTIAL ENERGY | SolveeIt | Solveeit

Today, August 18

Question

Potential energy of a satellite having mass ‘m’ and rotating at a height of $6.4 \times 10 ^ { 6 }$ m from the earth centre is

A

$- 0.5 m g R _ { e }$

B

$- m g R _ { e }$

C

$- 2 m g R _ { e }$

D

$4 m g R _ { e }$

Answer

$- m g R _ { e }$

Explanation

Solution

Potential energy $= - \frac { G M m } { r }$ $= - \frac { G M m } { R _ { e } + h }$ $= - \frac { G M m } { 2 R _ { e } }$

[As $h = R _ { e }$ (given)]

∴ Potential energy $= - \frac { g R _ { e } ^ { 2 } m } { 2 R _ { e } }$ $= - 0.5 m g R _ { e }$

[As $G M = g R ^ { 2 }$ ]