A force that opposes motion between the surface of two objects

The amount of matter in an object.

The force of gravity acting on an object's mass.

A natural force that attracts two object toward each other; depends on mass

Equal and opposite forces that cancel

Forces on an object that do not cancel

The sum of all forces

The tendency of an object at rest to stay at rest and an object in motion to stay in motion unless acted upon by an outside force.

A force opposing motion of an object through air.

The motion of an object when the only force acting on it is gravity

The constant velocity of a falling object experiencing balanced forces

The Law of Inertia

Net force is equal to mass of the object times its acceleration.

For every action force there is a reaction force of equal size and opposite in direction