1. 8th Science-Motion, Speed, Acceleration

2. Motion and Speed
Position-the location of an object
Motion—occurs when an object changes its position
*Motion doesn’t always have to be seen for a motion to have taken place
Reference Point-used to determine how far something moves
Ex: mailbox while driving, etc.

3. Distance and Displacement
Distance—describes how far something has moved
SI base unit to measure distance is- meter
Displacement—the distance and direction of an object’s change in position from the starting point (how far you are from where you started)-pg. 175

4. Speed Speed-the distance an object travels per unit of time
Ex: miles per hour/ feet per minute, etc.
Rate—any change over time
**Speed is a rate
Equation: Speed = Distance / Time
typically measured in m/s but could be km/hr or mph, etc.

5. Most speeds are not constant, they either slow down or speed up
Average speed-describes speed of motion when speed is changing-(total distance / total time)
Instantaneous Speed-speed at a given point in time
Ex: speed on an odometer in car
*pg. 177-distance/time graph

6. Velocity
Velocity--includes the speed of an object AND the direction of its motion
*Velocity can change even if speed remains constant
Change in Velocity—can be EITHER a change in speed OR in direction of movement
*Graph-pg. 179-complete

7. Plate Tectonics
The motion of the Earth’s crust creates the continental drifting that occurs every year
Plate Tectonics Theory-Pangea
Plates move so slowly that their speeds are given in units of centimeters per year.
Australian plate-1 of fastest—moves Australia north at an average speed of 17 cm./year