First slide
Gravitational force and laws
Question

An isolated triple star system consists of two identical stars, each of mass m and a fixed star of mass M. They revolve around the central star in the same circular orbit of radius r. The two orbiting stars are always at opposite ends of a diameter of the orbit. The time period of revolution of each star around the fixed star is equal to:

 

Moderate
Solution

Net gravitational force on any orbiting star provides necessary centripetal force.

So GMmr2+Gm24r2=mV2rV=G(4M+m)4r     T=2πrV=4πr3/2G(4M+m)

Get Instant Solutions
When in doubt download our app. Now available Google Play Store- Doubts App
Download Now
Doubts App