Two masses 1 kg and 2 kg are separated by 1m. The position where third mass should be placed from 1kg mass, such that the force on it is zero.

Let ‘M’ be the mass placed at a distance ‘x’ from the mass 1 kg.For force to be zero at ‘B’ i.e. (on ‘M’)   Force of attraction between two masses=GMmx2; universal gravitation constant=G; mass=m; distance=x;force on M due to 1kg mass = force on M due to 2kg massGM(1)x2=GM(2)(1−x)21−xx2=21x=2+1x=12+1m  from 1kg mass