Question

why we cannot push solid

Answer 1

To put quite simply, a force involves a push or a pull. Exerting a force on an object will cause that object to accelerate. Try pushing your finger against a wall. ... Because the wall is heavy, the force you exert on it does not move the wall noticeably.

Answer 2

Hey mate,

In solids the molecules (or atoms or ions) are permanently stuck in the same position, with permanent inter-molecular bonds. If you break these inter-molecular bonds, you permanently break them and make a new surface.

In contrast, in liquids the inter-molecular interactions are fleeting, they last picoseconds or less and are then replaced by new ones. Molecules change neighbours at very high frequency. You, breaking a connection with an external push-force, provide only a minor change.

Hope it helps.