Question

In which matter sliding over happens?

Answer 1

Answer:

in a slanted matter including oil sliding over happens

Answer 2

→ Sliding is a type of frictional motion between two surfaces in contact. This can be contrasted to rolling motion. Sliding may occur between two objects of arbitrary shape, whereas rolling friction is the frictional force associated with the rotational movement of a somewhat disclike or other circular object along a surface. Generally, the frictional force of rolling friction is less than that associated with sliding kinetic friction.

Hope it's helpful.. ^_^