1. Chapter 9: Motion and Forces
Section 1:
Describing Motion
Motion
Reference point
Distance
Displacement
Vector
Section 2:
Speed and Velocity
Speed
Average speed
Instantaneous speed
Velocity
Slope

2. Chapter 9: Motion and Forces
Section 3:
Acceleration
Section 4:
Energy
Work
Kinetic energy
Potential energy
Gravitational potential energy
Elastic potential energy
Mechanical energy
Law of conservation of energy

3. Describing Motion
Motion happens when the distance from one object to another changes.

4. Describing Motion
A Reference Point is a place or object used for comparison to determine if something is moving
Motion is different for different reference points The choice of reference point determines an object’s relative motion.

5. Describing Motion
Displacement is the length and direction that an object has moved from its starting point.
Distance is the total length of the path between two points.
Displacement is a vector, which is a quantity that has both magnitude (size) and direction.

6. Examples of Relative Motion#1
Train is moving 100kph relative to the tree/earth
Passenger is running 15kph towards the back of the train.
How fast is the runner moving toward the tree?
Direction of passenger
Tree
Direction of Train

7. Examples of Relative Motion#2
Train is moving 100kph relative to the tree/earth
Passenger is running 20kph towards the front of the train.
How fast is the runner moving toward the tree?
Direction of passenger
Tree
Direction of Train

8. Examples of Relative Motion#3
Train is moving 10kph relative to the tree/earth
Passenger is running 20kph towards the front of the train.
How fast is the runner moving from the tree?
Direction of passenger
Tree
Direction of Train

9. Examples of Relative Motion#4
Train is moving 10kph relative to the tree/earth
Passenger is running 10kph towards the back of the train.
How fast is the runner moving toward the tree?
Direction of passenger
Tree
Direction of Train