1. Negative Acceleration: Braking Your Automobile

2. Do Now  A car is traveling at 60 m/s, the driver sees a stoplight ahead and slows to a complete stop in 10 seconds. What is the car’s acceleration?  A motorcycle is passing a bus on a two lane highway and increases his speed from 40 m/s to 75 m/s in 5 seconds. What is the motorcycle’s acceleration?

3. Date: September 4, 2012 HW:PTG pg. 88, #1-4, Due Friday  Do Now (NB pg ?):  WDYS  WDYT  TB pg. 75  Read Investigate #1-4  TB pg. 76-77  Agenda:  Do Now  Objective & Success Criteria  Investigate  Physics Talk  Quiz 1.5  PTG  Learning Objective: Explain how negative acceleration relates to braking and stopping distance  Success Criteria:  Plan and carry out an experiment to relate braking distance to initial speed  Determine braking distance  Examine accelerated motion

4. Investigate: Initial Speed and Braking Distance  Materials:  List all materials for your lab today.  How will you use these materials to test initial speed and braking distance?

5. Investigate  Hypothesis:  With your group come up with a hypothesis for initial speed and braking distance using:  IF__________THEN__________ BECAUSE____________statement

6. Investigate:  Complete #1-3 with your group  Check procedures with Mr. LePera  Create data table  Check with Ms. LePera

7. HW:PTG pg. 88, #1-4, Due Thurs  Finish procedures and data table  Set up and collect data  Remember you are measuring the SPEED at the bottom of the ramp and BRAKING distance in METERS!  Analyze Data  Average speed AND distance for EACH height

8. HW:PTG pg. 88, #1-4,  Do Now:  Find Averages  Complete #5 a,b on pg. 77  One group member draw your graph on the board  Complete #5c-e  Agenda:  Do Now  Investigate 5-8  Physics Talk  Checking up  Quiz  Learning Objective: Understand how negative acceleration relates to braking and stopping distance  Success Criteria:  Plan and carry out an experiment to relate braking distance to initial speed  Determine braking distance  Examine accelerated motion

9. Investigate #5-8  As a class

10. Physics Talk  What is negative acceleration?  Draw an example of negative acceleration  Change in velocity with respect to time by decreasing speed in the positive direction or increasing speed in the negative direction

11. Physics Talk  How do you calculate braking distance?  V i 2 =-2ad vi2vi2 -2a d

12. Checking up pg. 82, #1-3

13. HW: None  Do Now:  Get out 1.5 PTG #1-4  Discuss answers with your group  Agenda:  1.5 PTG #1-4  1.5 Quiz  Computer Set up (p4)  Chapter Challenge Rubric  Chapter Challenge Work Day  Learning Objective: Understand how negative acceleration relates to braking and stopping distance  Success Criteria  Calculate negative acceleration and braking distance  Work on Chapter Challenge