Friction force
The force between two surfaces in contact that acts in a direction opposite to the direction of motion and causes the object to slow down and stop.
Friction force.
Is it easier to ski on grass or snow ?, Why ?
To ski on snow , as the snow is smooth ,The friction force depends on the type of the material directly in contact with the base of the snow scooter.
It is a type of friction force that happens when a body moves through air.
Air resistance