Mass M is divided into two parts xM and (1

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Mass $M$ is divided into two parts $xM$ and $(1 - x)\,M$. For a given separation, the value of $x$ for which the gravitational attraction between the two pieces becomes maximum is

A

$0.5$

B

$\frac{3}{5}$

C

$1$

D

$2$

Mass $M$ is divided into two parts $xM$ and $(1 - x)\,M$. For a given separation, the value of $x$ for which the gravitational attraction between the two pieces becomes maximum is

$F \propto xm \times (1 - x)m = x{m^2}(1 - x)$

For maximum force $\frac{{dF}}{{dx}} = 0$

$⇒$ $\frac{{dF}}{{dx}} = {m^2} - 2x{m^2} = 0\, \Rightarrow x = 1/2$