Term | Definition |
Reference point | is the starting point you choose to describe the location, or position of an object. |
Position | is an object distance and direction from the reference point |
Motion | is a process of changing position |
Displacement | is a different between the initial and the final position of an object |
Speed | A measure of distance an object travel per unit of time |
Constance speed | is a rate of change of position in which the same distance is travel each second |
Instantaneous speed | is speed at a specific instant in time |
Average speed | is the total distance traveled divided by a total time taken to travel that distance. |
Velocity | is the speed and direction of a moving object |
Acceleration | is a measure of change in velocity during a period of time |
Force | a push or pull on an object |
Contract force | a push or a pull on one object by another object that is touching it |
Non contract force | a force that one object applies to another object without touching it |
Gravity | an attractive force that exists between all objects that have mass |
Mass | the amount of matter in an object |
Weight | the gravitational force exerted on an object. |
Friction | the gravitational force exerted on an object. |
Net force | the combination of all the forces acting on an object |
Balanced forces | Balanced forces |
Unbalanced forces | forces acting on an object that combine and form a net force that is not zero |
Newton’s first law | law that states that if the net force acting on an object is zero, the motion of the object does not change |
Inertia | the tendency of an object to resist a change in motion |
Newton’s Second law | law that states that the acceleration of an object is equal to the net force exerted on the object divided by the object's mass |
Circular motion | law that states that the acceleration of an object is equal to the net force exerted on the object divided by the object's mass |
Centripetal | in circular motion, a force that acts perpendicular to the direction of motion, toward the center of the curve. |
Newton’s third law | law that states that for every action there is an equal and opposite reaction |
Force pair | the forces two objects apply to each other |
Momentum | a measure of how hard it is to stop a moving object. |
Law of conservation of momentum | a principle stating that the total momentum of a group of objects stays the same unless outside forces act on the objects. |
Sound wave | a longitudinal wave that can travel only through matter |
Pitch | the perception of how high or low a sound is; related to the frequency of a sound wave |
Echo | a reflected sound wave |
Energy | the ability to cause change. |
Kinetic energy | energy due to motion |
Electric energy | energy carried by an electric current. |
Potential energy | stored energy due to the interactions between objects or particles. |
Chemical energy | energy that is stored in and released from the bonds between atoms. |
Nuclear energy | energy stored in and released from the nucleus of an atom. |
Mechanical energy | energy stored in and released from the nucleus of an atom. |
Thermal energy | the sum of the kinetic energy and the potential energy of the particles that make up an object. |
Sound energy | energy carried by sound waves. |
Seismic energy | the energy transferred by waves moving through the ground. |
Radiant energy | energy carried by an electromagnetic wave. |
Energy transformation | - the conversion of one form of energy to another. |
Law of conservation of energy - | law that states that energy can be transformed from one form to another, but it cannot be created or destroyed |
Work | the amount of energy used as a force moves an object over a distance. |
Simple machines | a machine that does work using one movement. |
Inclined plane | a simple machine that consists of a ramp, or a flat, sloped surface. |
Screw | a simple machine that consists of an inclined plane wrapped around a cylinder. |
Wedge | a simple machine that consists of an inclined plane with one or two sloping sides; it is used to split or separate an object. |
Lever | a simple machine that consists of a bar that pivots, or rotates, around a fixed point. |
Wheel and axle | a simple machine that consists of an axle attached to the center of a larger wheel, so that the shaft and wheel rotate together. |
Pulley | a simple machine that consists of a grooved wheel with a rope or cable wrapped around it. |
Complex machines | two or more simple machines working together. |