# Contact force and intermolecular distance between two objects during free fall

I am a bit confused. When two objects are in a free fall such that when released to free fall they were one top of another, will there be any contact force between the two objects and will there be a change in intermolecular distance to when they we at rest , also one top of another. Ignore air drag. Will they remain together or what?

Is there a contact force between two bodies one top of another like a book on table perfectly smooth free falling and if the contact force disappears that what happen please explain in detail.

Also why are objects pushed up as soon as they start free fall why cant they remain where they are.

There will not be any contact force between two freely falling bodies. Note that contact force on a smooth surface is called normal $$\mathbf {reaction}$$. This force is a reaction to other external forces. If you wish to easily find out this force, you should move to the frame of the table. Then you will notice that the weight of the book is canceled by pseudo force added since we are in a non-inertial frame. So normal reaction must be zero, since book is in equilibrium from table frame. All this of course happens if we neglect air drag.
• Because the relative $g$ is zero Commented May 17, 2021 at 9:15