1. Intro to Forces C-Notes
Motion and Forces

2. 2 Categories : contact and non-contact
What is a Force?
a Force is a push or pull.
2 Categories : contact and non-contact
Contact Force
exerted when two objects are touching.
Non-contact Force
exerted on one object by another when the objects are NOT touching.

3. Force is a VECTOR because it has magnitude (size) and direction
UNIT of measurement for force is the Newton (N).
We represent forces using FORCE VECTOR ARROWS
What is a Force ? (cont’d)
15 N

4. When 2 or more forces act on an object, the forces combine.
Combining Forces
When 2 or more forces act on an object, the forces combine.
The NET FORCE is the sum of ALL forces acting on an object.
When net force = 0 N, forces are BALANCED.
The velocity of the object doesn’t change (no acceleration)
When net force ≠ 0 N, forces are UNBALANCED.
The velocity of the object changes (acceleration)