Question

we can easily move the wooden block when it is rolling over a surface than sliding why?​

Answer 1

Explanation:

It is much more easy to move the book placed on rollers then to slide it directly over the surface of table. It is much easier to move an object kept on rollers then to slide it because rolling friction is much less than sliding friction.

Answer 2

Air is a gas, it has more space in between particles. But solid block of wood is rigid, hence it is difficult to move our hands through it.