1. Newton’s Laws of Motion

2. Newton’s First Law of Motion
An object in motion will stay in motion, and an object at rest will stay at rest, unless acted upon by an equal or opposite force.

3. This Photo by Unknown Author is licensed under CC BY-SA

6. Sometimes an object STOPS because of Friction
Friction is the force between two surfaces that prevents those surfaces from sliding or slipping across each other.
Friction occurs when objects that are in motion come in contact with each other and their surfaces are not smooth.
Friction occurs between two solid objects. When this happens with a solid object and a gas or air, we call this air resistance.
Friction (or air resistance) is one of the forces that can act on an object’s inertia.
Without friction, some objects wouldn’t be able to move forward. For example, your feet wouldn’t propel against the ground—you would just run in place.