^^Free-Body Diagram^^: a sketch that shows an object and the forces acting on it; also called a force diagram
Gravity
Friction
Types of friction:
^^Traction^^: the frictional force between a vehicle’s ires and the road; responsible for accelerating the vehicle
^^Centripetal Force^^: a force that accelerates an object toward the center of a circular path
^^Fundamental Force^^: any one of the four forces that appear to underlie all the other known forces: gravity, strong force, weak force, and electromagnet force