# Science Vocabulary

## Motion

The action or process of moving or of changing place or position or movement

## Mass

A unified body of matter with no specific shape

## Force

The capacity to do work or cause physical change energy, strength, or active power

## Balanced Forces/ Unbalanced Forces

Balanced Force: Forces are balanced when the forces pushing (or pulling) an object in one direction are the same size as the forces acting in the opposite direction.

Unbalanced Force: Pulling force exerted by a string, cable, chain, or similar solid object on another object

## Work

Activity involving mental or physical effort done in order to achieve a purpose or result

## Speed

The rate at which someone or something is able to move or operate

## Distance

An amount of space between two things or people

## Time

Continued progress of existence and events in the past, present, and future

## Velocity

The speed of something in a given direction

## Acceleration

Increase in the rate or speed of something

## Deceleration

Decrease in the rate or speed of something

## Energy

The property of matter and radiation that is manifest as a capacity to perform work (such as causing motion or the interaction of molecules)

## Newton's Law of Inertia

Newton's first law states that a body at rest will remain at rest, and a body in motion will remain in motion with a constant velocity, unless acted upon by a force

## Newton's Law of Force and Acceleration

The behavior of objects for which all existing forces are not balanced. The acceleration of an object is dependent upon two variables - the net force acting upon the object and the mass of the object

## Newton's Law of Action-Reaction

According to Newton, whenever objects interact with each other, they exert forces upon each other. When you sit in your chair, your body exerts a downward force on the chair and the chair exerts an upward force on your body. There are two forces resulting from this interaction - a force on the chair and a force on your body. These two forces are called action and reaction forces and are the subject of Newton's third law of motion

## Displacement

The moving of something from its place or position

## Friction

The resistance that one surface or object encounters when moving over another

## Free Fall

Downward movement under the force of gravity only

## Momentum

The quantity of motion of a moving body, measured as a product of its mass and velocity

## Projectile

An object propelled through the air, one thrown as a weapon

Example: A missile designed to be fired from a rocket or gun

## Period

A length or portion of time

## Frequency

The rate at which something occurs or is repeated over a particular period of time or in a given sample

## Centripetal Force

A force that acts on a body moving in a circular path and is directed toward the center around which the body is moving

## Centripetal Acceleration

The acceleration toward the center that holds a satellite in elliptical orbit

## Newton (SI unit not Sir Newton)

The newton (symbol: N) is the International System of Units (SI) derived unit of force It is named after Isaac Newton in recognition of his work on classical mechanics

## Inertia

Resistance of any physical object to any change in its state of motion: it is the tendency of objects to keep moving in a straight line at constant linear velocity