1. Motion Section 1

2. Frames of Reference
The background or object used for comparison is a frame of reference.
Example: Riding in a car. Are you moving or not?
Earth is a universal frame of reference.
Ex. You are moving 30km/s right now.

3. Distance How far an object travels in total.
Can be measured in kilometers, centimeters or meters.
If you run once around a track your total distance is 400m

4. Displacement How far you are at the end compared to where you started.
Includes the direction you are compared to where you started.
EX. If you run around a track one full time, the distance you traveled is 400m but your displacement is 0.

5. Speed Speed is the change in position in a certain amount of time.
Baby Crawling – 1km/hr
Car- 80 km/hr
Cheetah – 110 km/hr
Jet – 3600 km/hr

6. Calculating Speed Speed = Distance Time
Units are always meters per second m/s or kilometers per hour km/hr.
Example: A person walks 10km in 2 hrs. What is the average speed of the person.

7. Practice A car travels 240 km in 3 hrs. What is the speed of the car.
A baseball is thrown a distance of 60 meters in 2 seconds. What is the speed of the baseball.

8. Average vs. Instantaneous
When we calculate speed d/t, this is the average speed.
Instantaneous speed is our speed at any point in time.
Speedometers measure a cars instantaneous speed.

9. Graphing Motion Uses a distance vs. time graph.
Which swimmer is faster?
What if the line was a flat horizontal line?
Slope tells you the speed of the object.

10. Velocity
Velocity is similar to speed except that it includes the direction of its motion.
A car’s speed may be 30km/hr.
Its velocity may be 30km/hr North.