1. Motion

2. Event that involves a change in the position or location of something.
Definition
Event that involves a change in the position or location of something.

3. Motion is Relative
Relative – it is described compared to a REFERENCE POINT

4. Types of Motion Uniform motion - constant speed in a straight line
Accelerated motion – motion that is changing in speed or direction
Circular motion - speed is constant but the direction of motion is changing continuously

5. Scalar Quantities Show magnitude [amount] only
Speed, time, temperature

6. Vector Quantities Show magnitude and direction
Velocity, acceleration, force
May be graphically represented
Arrows

7. Speed Average Speed Comparison of time and distance
A scalar quantity [magnitude only]
Distance traveled per unit time
S = d / t
T = d / s
D = s x t

8. Speed Instantaneous Speed
Speed at any instant

9. Speed Constant Speed Speed that does not change
Instantaneous speed that does not change

10. Velocity
Speed AND direction
A vector quantity [magnitude & direction]

11. Acceleration A change in velocity Speeding up Slowing down
Positive acceleration
Slowing down
Negative acceleration
Deceleration
Changing direction

12. Forces Pushes or pulls May cause acceleration [changes in motion]
May also cause changes in shape

13. Balanced Forces All forces acting on an object are equal
There is no motion

14. Unbalanced Forces All forces acting on an object are not equal
One or more force is stronger than others
Motion occurs

15. Net Force The sum of all forces acting on an object A net force of 0
No motion
A net force of more than 0
Motion occurs

16. Resultant
Another term for net force

17. Friction Force that slows down motion
Air resistance creates friction in most situations

18. Gravity Force that attracts all objects toward each other
More mass = more gravity
Acceleration because of gravity is 9.8 m/s/s
All objects accelerate at the same rate

19. Newton's Laws
Describe motion and changes in motion

20. First Law of Motion Law of inertia
Objects at rest [not moving] will not begin to move until a force acts on them
Objects in motion will not stop moving until a force acts on them
Objects with more mass have more inertia
Bigger objects are harder to start and stop

21. Second Law of Motion Law of acceleration
A force is needed to change motion
Objects accelerate in the direction of the force
The more force applied, then more acceleration
The more mass an object has, the more force is needed to accelerate the object

22. Third Law of Motion Law of action-reaction Forces occur in pairs
The forces are equal and opposite
One force is an action force
The other force is a reaction force
The forces act on different objects