Question 1:
easy
Two identical spheres each of mass M and radius R are separated by a centre to centre distance 10R. The gravitational force on mass m placed at the midpoint of the line joining the centres of the spheres is :
At the midpoint, the gravitational forces exerted by the two identical spheres on the mass \( m \) have the same magnitude but act in opposite directions. Since these forces cancel each other out completely, the net gravitational force on the mass \( m \) is:
\[
F = 0
\]