Q5 of 81 Page 225

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.

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.




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(a) The mid-point of a side,


(b) At the Centre of the triangle.


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