1. Newton’s First Law of Motion
Inertia- the tendency of an object to resist change. The greater the mass the greater the inertia!

2. Force Force- Push or a pull on an object
Object speeds up, slows down, or turns from force
More than one force can act on an object at the same time
Net Force- Combination of all the forces acting on an object.
Force= Mass X Acceleration

3. Balanced and Unbalanced Forces
Balanced Forces- Two or more forces exerted on an object that cancel each other and do not change object’s velocity
Net force is zero
Unbalanced Forces- Effects of the forces don’t cancel and the object’s velocity changes
Net force is not zero

4. Newton’s First Law of Motion
Isaac Newton ( )- Explained motion of objects in 3 laws of motion
Newton’s First Law of Motion-
An object at rest will stay at rest, an object in motion at constant velocity will continue at a constant velocity unless acted upon by an unbalanced force.

5. Friction
Friction- Force that acts to resist sliding between two touching surfaces.
Ex: Acts on objects moving through air or water

6. Friction
Static Friction- Type of friction that prevents an object from moving when force is applied. (object at rest)
Caused by attraction of atoms on the two surfaces that are in contact

7. Friction
Sliding Friction- Type of friction that is due to the roughness of the two objects.
Slows down object that slides

8. Friction
Rolling Friction- Occurs when an object rolls across a surface
Rolling friction is less than sliding friction