A body of mass 2 M splits into four masses { m , M - m , m , M - m } , which are rearranged to form a square…

A body of mass 2M splits into four masses {m,M-m,m,M-m}, which are rearranged to form a square as shown in the figure. The ratio of Mm for which, the gravitational potential energy of the system becomes maximum is x : 1. The value of x is ________.

Solution

U=Gm2a+G(M-m)2a+2Gm(M-m)a+2Gm(M-m)2a

For maxima or minima of potential energy dUdm=0

dUdm=Ga(2 m-2(M-m)+(M-2 m)2+2(M-2 m)

(4m-4m-22m)+(-2M+2M+2M)=0;  2M=22m;  Mm=2

Asked in: JEE Main 2021 (27 Aug Shift 1)

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