Friction

Air resistance

Magnetic forces

Smooth surfaces

Intermolecular bonds and surface roughness

The force that resists the start of motion

The force that accelerates an object

The force that acts perpendicular to the motion

The force that slows down a moving object

A measure of the normal force

A measure of the roughness between two surfaces

A measure of the gravitational force

A measure of the applied force

The force parallel to the surface

The force due to gravity

The force perpendicular to the surface

The force due to friction

The force parallel to the surface

The force of friction

The force perpendicular to the surface

The force of gravity