JEE Main20198 Apr 2019Morning ShiftPhysicsGravitationActual
Four identical particles of mass M are located at the corners of a square of side ‘ a ’ . What should be their speed if each of them revolves under the influence of other’s gravitational field in a circular orbit circumscribing the square?
Options
- A1.35 G M a
- B1.21 G M a
- C1.41 G M a
- D1.16 G M a
Correct answer
D. 1.16 G M a
Step-by-step solution
Gravitational force on each mass 'M' = 2 G M 2 a 2 + G M 2 2 a 2 = 2 + 1 2 G M 2 a 2 This force will provide required centripetal force 2 + 1 2 G M 2 a 2 = M v 2 ( a / 2 ) v = 1 + 1 2 2 G M a = 1.16 G M a