Download Force and Motion Vocabulary

Eighth Grade
Science Force and Motion Vocabulary, S8P3
Force and Motion Vocabulary
Motion: A change in position over time.
Speed: The rate at which position changes. Speed includes distance and time. The formula to
find speed is d/t.
Instantaneous Speed: The speed traveled at any moment in time.
Average Speed: The total distance divided by the total time.
Velocity: Speed in a particular direction.
Acceleration: The rate at which velocity changes.
Friction: The force that opposes motion between two objects that are touching.
Inertia: a property of matter based on mass that has to do with an objects resistance to a change
in the state of motion. The object doesn’t want to change direction, speed up, slow down, stop or
start moving.
Force: A push or a pull.
Balanced Forces: Do not cause a change in the state of motion. The net force is ZERO!!
Unbalanced forces: Unbalanced forces do have a change in the state of motion, these cause
objects to change direction, speed up, slow down, stop or start moving.
Newton’s First Law of Motion: Objects at rest stay at rest and objects in motion stay in motion
unless acted on by an unbalanced force.
Newton’s Second Law of Motion: The more mass an object has the more force needed to
accelerated that object, the object will accelerate in the direction of the force.
Newton’s Third Law of Motion:
For every action there is an equal and opposite reaction.
Work: Work is when a force is applied and an object moves.
Simple Machine: are machines upon which all other machines are based. Simple machines
work by changing the amount, speed, or direction of the force.
Inclined Plane: A flat surface that is higher on one end- a slanting surface connecting a lower
level to a higher level.
Screw: An inclined plane wrapped around a cylinder.
Eighth Grade
Science Force and Motion Vocabulary, S8P3
Wedge: A wedge is usually made up of two inclined planes. A wedge is a simple machine used
to push two objects apart.
Wheel and Axle: A wheel with a rod, called an axle through its center lifts or moves loads.
Lever: A lever is a board or bar that rests on a turning point called a fulcrum.
Pulley: Instead of an axle, the wheel could also rotate a rope or cord. This is a variation of the
wheel and axle, it is the pulley.