Two small bodies of masses 10 kg and 20 kg are kept a distance 1.0 m apart and released, assuming that only mutual gravitational forces are acting find the speeds of the particles when the separation decreases to 0.5 m.
The linear momentum of 2 bodies is 0 intially. since gravitational force is internal, final momentum is also zero.
Since P.E.is conserved,
Initial P.E. =−6.67×1011×10×201=−13.34×10−9J
When separation is 0.5 m