JEE Main2018PhysicsGravitationActual
A particle is moving with a uniform speed in a circular orbit of radius R in a central force inversely proportional to the n t h power of R. If the period of rotation of the particle is T, then:
Options
- AT ∝ R n / 2
- BT ∝ R 3 / 2 for any n
- CT ∝ R n 2 + 1
- DT ∝ R n + 1 2
Correct answer
D. T ∝ R n + 1 2
Step-by-step solution
F = K R n ⇒ m V 2 r = K R n ⇒ V 2 ∝ K R n - 1 ⇒ V ∝ 1 R n - 1 2 ⇒ T = 2 π R V ∝ R V ⇒ T ∝ R 1 R n - 1 2 ⇒ T ∝ R n + 1 2