Speed: the distance an object travels per unit of time.

Velocity: speed in a given direction.

Acceleration: the rate of which velocity changes.

Force: a push or pull exerted on an object

Newton(N): a unit on measure that equals the force required to accelerate 1 kilogram of a mass at 1 meter per second per second.

Net force: the overall force on an object when all individual forces acting on it are added together.

Friction: the force that two surfaces exert on each other when they rub against each other.

Static friction: friction that occurs when one solid surface slides over another.

Rolling friction: friction that occurs when an object rolls over a surface.

Fluid friction: friction that occurs as an object moves through fluid or air.

Gravity: the attractive force between objects; the force that moves objects downhill

Mass: a measure of how much matter is in an object

Weight: a measure of the force of gravity acting on an object.

Inertia: the tendency of an object to resist to change in motion.