1. A force is defined as a push or a pull that acts on an object.
Forces
A force is defined as a push or a pull that acts on an object.

2. Characteristics of a Force
wants to change the motion of an object
has size
has direction
can change speed
can change direction

3. SI unit of Force= Newton
A Newton is a metric unit of weight
1 Newton = 1 kg m/s2

4. Force of Gravity
Force of gravity is the downward force exerted by the earth on an object.
Force = mass x acceleration due to gravity
F= ma
Acceleration due to gravity = 9.8 m/s2

5. Contact vs Non-contact
Contact: there is contact between what is exerting the force and what is receiving the force
Non-contact: the result is visible but you cannot see the contact between the force and the agent, example gravity

6. Net Force combination of all of the forces
determined by the directions of the forces
shown by vectors

7. Vector arrow attached to the receiver of the force
length = magnitude of the force
direction shown by the arrow head
→, ↓, ↑, ←

8. Net force Forces in the same direction: add the forces together
Forces in different directions: subtract the smaller force from the larger one

9. Balanced Forces net force = 0 no change in motion
an object at rest will stay at rest

10. Unbalanced Force Net force ≠ 0 change in speed change in direction
object at rest will move
object moving might stop