JEE MainPhysicsGravitation
Two satellites P and Q , having masses m and 3m respectively, are revolving in circular orbits around a planet. If the orbital speeds of both the satellites are equal, which of the following physical quantities must also be identical for them?
Options
- ATime period of revolution
- BKinetic energy
- CAngular momentum
- DCentripetal force
Correct answer
A. Time period of revolution
Step-by-step solution
The orbital speed of a satellite is given by v = GM r , where M is the mass of the planet and r is the orbital radius. Since both satellites have the same orbital speed, their orbital radii r must be equal. The time period of revolution is T = 2 r v . Since both r and v are identical for the two satellites, their time periods must also be equal. The other quantities depend on the mass of the satellite: Kinetic energy K = 1 2 mv^2 Angular momentum L = mvr Centripetal force F = mv^2 r Because their masses are differe