Force
A push or a pull
Speed
the distance traveled divided by the time interval(d/t).
Velocity
the speed of an object in a particular direction
Acceleration
the rate at which velocity changes over time
Free fall
the motion of the body when only the force of gravity is acting on the body
Net Force
The combination of all forces acting on an object
Friction
The force that one surface exerts on another when the two rub against each other
Static Friction
a friction force that acts on objects that are not moving
Fluid Friction
friction that occurs as an object moves through a fluid
Rolling Friction
friction that occurs when an object rolls over a surface
Sliding friction
a friction force that opposes the motion of an object as it slides over a surface
Air Resistance
force that opposes the motion of objects that move through the air
Gravity
Attractive force between two objects that depends on the masses of the objects and the distance between them.
Inertia
Resistance of an object to a change in its motion
Mass
A measure of the amount of matter in an object
Weight
A measure of the gravitational force exerted (pushing) on an object.
Gravitational Force
an attractive force that acts between any two objects
Distance
the space that exists between two points
Terminal Velocity
the constant velocity of a falling object when the force of air resistance equals the force of gravity and the object stops accelerating toward the earth