Question

An apple attracts the earth and the earth also attracts the apple towards its centre. Then, why only apple falls towards the earth but earth is not moved towards the apple ?

Answer 1

The gravitational forces acting on both the apple and the earth (or a stone and earth) are equal in accelaration produced in the apple or stone is very large and the acceleration produced in the earth magnitude. Since, the mass of the apple or stone is very small as compared to the mass of the earth, so the
is negligible. That is why, the motion of the earth is not noticed.