Inertia, Forces, and Newton's 1st Law Vocab

Newton's 1st Law

An object at rest remains at rest and an object in motion remains in motion at constant speed and in a straight line unless acted on by an unbalanced force (Law of Inertia)

Force

A push or pull; all forces have both size and direction

Balanced Forces

Happen when 2 forces acting in opposite directions are equal in size (Net Force = 0)

Newton (N)

The unit used to measure force

Inertia

The tendency of all objects to resist any change in motion

Momentum

A property of a moving object that depends on the object's mass and velocity

Friction

A force that opposes motion between two surfaces that are touching

Unbalanced Forces

Happen when 2 forces acting in opposite directions are NOT equal in size (Net Force > 0)

Sliding Friction

Pushing a solid over a solid

Rolling Friction

Wheels reduce friction so things are easier to move

Fluid Friction

The force between solids and a liquid or gas.

Static Friction

This force balances others so the object does not move

Gravity

A force of attraction between two objects that is due to their masses

Law of Universal Gravitation

The scientific law that states that every object in the universe attracts every other object *Force increases as mass increases. *Force decreases as distance increases.

Mass

The amount of MATTER in an object; its value DOES NOT CHANGE

Weight

A measure of the gravitational force exerted on an object

Net (Resultant) Force

The force that results from combining all the forces exerted on an object