Weight of a body is less in the mines. Why?
The weight of a body is less in the mines because when we move deeper the earth gravity decreases but our mass is always constant.
Two bodies on the surface of the earth do not move towards each other due to the force of attraction given by Newton's law of gravitation. Why?
As we all know that, each and every body in the universe is attraction each other according to Newton's law of gravitation. But not only a body is affected by the gravitational force of a single body but also it is affected by several other forces which get balanced. So, two bodies on the surface of the earth don't move towards each other.