1. Warm-up  Get your green folder  Open to notebook paper and label it “ Speed and Motion Notes”  Make sure your have something to write with  Write the formula for speed at the top of your new page  If you are out of paper add three more pages of notebook paper to your brads

2. Objective 6.8- Changes in Force and Motion Calculate average speed using distance and time measurements

3. Speed and Motion Measuring Motion Notes

4. Directions  As you go through the PowerPoint take notes.  Be sure to include the subtitles for each different section so your notes are organized and understandable.  Only copy “Question” slides if you feel they will be helpful to you as review.

5. Measuring Distance  How you measure distance will depend on what you are doing.  Meter – international unit for measuring distance. 1. km – long distances 2. m – medium distances 3. cm – small length 4. mm – tiny length = 50 m 1 mm

6. Measuring Time  The time used will also depend on what you are doing. Driving is usually hours (hr) Walking is minutes (m) Racing could be in seconds (s)

7. Calculating Speed  divide the distance by the time to figure out how far you traveled in a single unit of time. Speed = Distance Time Speed (S) = distance traveled (d) the amount of time it took (t). S = d/t

8. What is speed? When you calculate average speed, you are figuring out how far you go for ONE unit of time (1 second; 1 minute; 1 hour). 50 km If travel 10 km/hr that means it takes you ONE HOUR to go TEN km. 10 km

9. Units for speed  The units depend, but will always be a distance unit over a time unit Ex. Cars: mi./h (miles per hour) Jets: km/h (kilometers per hour) Snails: cm/s (centimeters per second) Falling objects: m/s (meters per second)

10. Calculating speed  If I travel 100 kilometer in one hour then I have a speed of…  100 km/h  If I travel 1 meter in 1 second then I have a speed of….  1 m/s S = d/t

11. Average speed  Speed is usually NOT CONSTANT Ex. Cars stop and go regularly Runners go slower uphill than downhill  Average speed = total distance traveled/total time it took.

12. Calculating Average Speed  It took me 1 hour to go 40 km on the highway. Then it took me 2 more hours to go 20 km using the streets.  Total Distance: 40 km + 20 km = 60 km  Total Time: 1 h + 2 h = 3 hr  Ave. Speed: total d/total t = 60 km/3 h = 20 km/h

13. Question  I ran 1000 m in 3 minutes. Then ran another 1000 m uphill in 7 minutes. What is my average speed? A) 100 m/min B) 2000 m/min C) 10 m/min D) 200 m/min E) 20 m/min Total Dist. = 1000 m + 1000 m = 2000 m Total Time = 3 min + 7 min = 10 min Ave speed = total dist/total time = 2000m/10 min = 200 m/min = D

14. Graphing Speed: Distance vs. Time Graphs Phoenix Denver

15. Different Slopes Run = 1 hr Rise = 0 km Rise = 2 km Rise = 1 km Slope = Rise/Run = 1 km/1 hr = 1 km/hr Slope = Rise/Run = 0 km/1 hr = 0 km/hr Slope = Rise/Run = 2 km/1 hr = 2 km/hr

16. Graphing Motion: Speed vs. Time Graphs 1)Speed is increasing with time = accelerating 2)Line is straight = acceleration is constant

17. Graphing Motion: Distance vs. Time Graphs 1)On Distance vs. Time graphs a curved line means the object is accelerating. 2)Curved line also means your speed is increasing. Remember slope = speed.

18. Question: 1)Which line represents an object that is accelerating? The black and red lines represent a objects that are accelerating. Black is going a greater distance each second, so it must be speeding up. Red is going less each second, so must be slowing down Remember: in distance vs. time graphs: curved line = accelerating, flat line = constant speed