Can you think of two particles which do not exert gravitational force on each other why? `(AS_(2))`

Two spherical balls of mass 10 kg each are placed with their centers 10 cm apart. Find the gravitational force of attraction between them. (AS_(1))

What is called maximum distance for which the molecules can exert attraction force on each other ?

Two stationary particles of masses M_(1) and M_(2) are at a distance d apart. A third particle, lying on the line joining the particles experiences no resultant gravitational forces. What is the distance of this particle from M_(1) .

Three particles, each of the mass m are situated at the vertices of an equilateral triangle of side a . The only forces acting on the particles are their mutual gravitational forces. It is desired that each particle moves in a circle while maintaining the original mutual separation a . Find the initial velocity that should be given to each particle and also the time period of the circular motion. (F=(Gm_(1)m_(2))/(r^(2)))

Can two streamline cross each other ? Why ?

Why do two electric field lines not intersect each other ?

A particle of mass m is placed at each vertices of equilateral triangle. If the particle of 5 kg is placed at the centroid of triangle, then find the gravitational force on it. The distance between centroid to vertice is 2 m.