Two bodies of masses $$8 \mathrm{~kg}$$ are placed at the vertices $$A$$ and $$B$$ of an equilateral triangle $$A B C$$. A third body of mass $$2 \mathrm{~kg}$$ is placed at the centroid $$G$$ of the triangle. If $$A G=B G=C G=1 \mathrm{~m}$$, where should a fourth body of mass $$4 \mathrm{~kg}$$ be placed, so that the resultant force on the $$2 \mathrm{~kg}$$ body is zero?

The value of acceleration due to gravity at a height of $$10 \mathrm{~km}$$ from the surface of earth is $$x$$. At what depth inside the earth is the value of the acceleration due to gravity has the same value $$x$$ ?

A satellite is orbiting close to the earth and has a kinetic energy $$K$$. The minimum extra kinetic energy required by it just overcome the gravitation pull of the earth is