The atmosphere is held to the earth by

How much force of gravitation acts on a body at an infinite distance from the Earth?

Draw a schematic diagram of Cavendish's experiment for the determination of the universal gravitational constant $G$ and obtain the formula used in it.

$A$ straight rod of length $L$ extends from $x = a$ to $x = L + a$. The gravitational force it exerts on a point mass $m$ at $x = 0$,if the mass per unit length of the rod is $A + Bx^2$,is given by

Two identical solid copper spheres of radius $R$ are placed in contact with each other. The gravitational attraction between them is proportional to

According to Newton's law of gravitation,every object in the universe exerts a gravitational force on every other object. Why do two objects not move towards each other?