Coefficient of friction: a numerical value relating the normal force exerted on an object to the force of friction exerted on the object. It depends on the surface properties of the materials in contact with each other.

Computational Model: a graphical representation of data which allows one to analyze and explore simple and complex systems using a computer to speed calculations.

Normal force: a force exerted due to contact between two objects that is always perpendicular to the plane of contact.

Rapid Braking Event (RBE): a driving situation where rapid decrease in velocity occurs such as when a driver has to apply the brakes in an emergency situation.