Two bodies of masses m and 4m are placed at a distance r

• Gravitation

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

1. zero
2. -4Gm/r
3. -6Gm/r
4. -9Gm/r

Answer

Gm/x² = G(4m)/(r-x)²

1/x = 2/(r-x)

r - x = 2x

3x = r

x = r/3

The correct option is D.