1. Warm-Up:
When creating a graph, which axis is independent and which is dependent?

2. Objective
Use a position vs speed graph to predict the speed of a car at a certain location.

3. Agenda Solving for Unknowns - Calculating Speed Graphing Review
Predicting Speed

4. Solving for Unknowns
Product equations
D=rt
A=bh
A=pi*r2

6. Distance = rate x time
Anytime I cross the horizontal line, I divide. Anytime I cross the vertical line, I multiply!

7. What about more complex problems?

8. Foldable to solve any science word problem
GUESS
Foldable to solve any science word problem

15. Graphing Review

16. Independent vs Dependent AxisY -1 1
Independent: x-axis
Dependent: y-axis
From the Lab: Is position independent or dependent?

17. Set Up Your Graph Label your x- and y-axes.
REMEMBER TO INCLUDE UNITS!
Use an equal scale between values:
i.e. each line is 1, 5, 10, etc.
Plot your points

18. Line of Best Fit Straight-line that best represents your data.
It does not necessarily “connect” your data points.
Represents the trend of your data.

19. Using Graphs to Interpolate Data
Predictions made between known data points.

20. Finish Your Graph
Draw your line of best fit, USE A RULER for best results.
Interpolate the speed of your car at a position not recorded during the lab.
Test your interpolated result with actual results by moving the photogate to your interpolated position and recording the car.
Calculate the speed & compare it to your prediction.

21. Post-Lab Questions:
Was your interpolated result close to your actual result?
Calculate the percent error of your interpolated result:
What could be the cause of your error? Remember, NO ONE has 0 error.

22. Practice Problems:
A football field is about 100 m long. If it takes a person 20 seconds to run its length, how fast (what speed) were they running?
The pitcher’s mound in baseball is 85 m from the plate. It takes 4 seconds for a pitch to reach the plate. How fast is the pitch?
If you drive at 100 km/hr for 6 hours, how far will you go?
If you run at 12 m/s for 15 minutes, how far will you go?
Every summer I drive to Michigan. It is 3900 km to get there. If I average 100 km/hr, how much time will I spend driving?

23. Exit-Ticket
Average speed is the speed a object travels over a given distant.
Instantaneous speed is the speed of an object at a particular instant in time.
Which speed did you calculate during this lab? Support your answer.