Four particle of equal masses M move along a circle of radius R under the action of their mutual gravitational attraction. Find the speed of each particle.

Question

Philoid · Accepted Answer

Here, P,Q,R and S are four particles of mass , moving in a circle of radius R.

The force between A and B is,

The force between A and D is also

Therefore, net force in downward direction is,

And force between A and C is also

Hence, net force on particle A is

Now this force provides for the centripetal acceleration in a balanced condition. Let v be the velocity of the mass.