Physics The study of physical forces and qualities: the scientific study of matter, energy, force, and motion, and the way they relate to each other The study of matter, motion, energy and forces.

Displacement The difference between the initial position and the final position of an object that has moved. Object that has moved from its original place to somewhere else.

Motion Changing your location or position. The process of changing places.

Speed The distance an object moves in a unit of time. How far something travels over a certain amount of time.

Constant Speed When an object moves the same distance over a given unit of time, it is said to have a constant speed. When an object moves from place to place at the same speed.

Changing Speed When the distance an object covers increases or decreases over a given unit of time. The distance an object can travel in an amount of time either increases or decreases.

Average Speed You calculate the average speed by dividing the total distance by the total time. The most common speed hit over a period of time.

Velocity The speed and direction of a moving object. How fast an object travels and the direction that it moves.

Constant Velocity An object moves with constant speed and its direction does not change. An object maintains a constant speed without changing its direction.

Changing Velocity The velocity changes when an object’s speed or direction changes. When velocity is altered.

Acceleration A measure in the change of velocity in a period of time. Measure of how quickly the speed and/or direction of an object changes.

Force To pull or push an object. Pushing or pulling on something.

Contact Force A push or a pull on one object by another object that is touching it. A push or pull motion on one item by another touching it. Friction is the most common contact force.

Noncontact Force A force that one object applies to another object without touching. To add pressure to an object without touching it. Gravity and magnets produce noncontact forces.

Gravity An attractive force that exists between all objects that have mass. A force that keeps us on the ground. (noncontact)

Friction Force that resists the sliding motion of two surfaces that are touching. When two surfaces rub together, they resist sliding motion. Contact force

Balanced Forces Forces acting on an object that combine and form a net force of zero. When forces push and pull on an object equally.

Unbalanced Forces Forces acting on an object that combine and form a net (total) force that is not zero. Pushing on different parts of an object causing movement.

Newton’s First Law of Motion Law of Inertia Forces acting on an object is zero, the motion of an object does not change. 8 th Grades Terms Inertia-An object will continue to do what it is doing. An object in motion will remain in motion until another force acts upon it.

Newton’s Second Law of Motion Law of Acceleration Acceleration = Force divided by mass 8 th grade terms An object’s motion will change in the direction of and proportional to the force acting upon it.

Newton’s Third Law of Motion The Law of Reaction For every action there is an equal and opposite reaction.