Two bodies of masses m and 4m are placed at a distance r. Calculate the gravitational potential at a point on the joining them where the gravitational field is zero.

Explanation

Given: `m_(1)=m`
`m_(2)=4m`
distance = r
To find: V = ??

`(Gm)/(x^2)=(G(m.4))/((r-x)^(2))`
`(r-x)^(2)=4x^(2)rArr(r-x)=2x`
`r=3x`
`thereforex=(r)/(3)`
`V=(Gm)/(r//3)-(G(4m))/(2r//3)`
`=-(9Gm)/(r)`