9/9/09

Post date: Sep 08, 2009 8:0:57 PM

Bell Ringer: When will acceleration be a large value? When will it be a small value? When will it be negative?

- Acceleration lab - due Friday
  - Acceleration Lab Instructions
    - Forming Teams
    - Work in groups of at least 5, no more than 7 students
    - Decide on a job for each person, according to the descriptions on the next slide
    - Jobs
    - 1. Timer for first 3 meters
    - 2. Timer for last 3 meters
    - 3. Timer for entire run
    - 4. Accelerator
    - 5. Acceleratee
    - 6. Recorder
    - 7. Recorder
    - The timers will be timing sections of a movement with acceleration. One will time only the first 3 meters, another only the last 3, and the 3^rd will time from start to finish
    - The accelerator pushes the chair
    - The acceleratee sits in the chair
    - The recorders record data
    - Data to record
    - Be sure to record the total time, the time for the first 3 meters, and the time for the last 3 meters
    - Do this twice, in case your data doesn’t work out from the first trial
    - Calculations
    - Find the average speed for the entire run
    - Find the average speed for the first 3 meters
    - Find the average speed for the last 3 meters
    - Find the average acceleration for the entire run (assume your first speed happens at 0 seconds, and your end speed happens at the very end of your time for the run)
    - Analysis
    - Make a graph of speed vs. time for your entire run
    - Assume that the speed for the first 3 meters happens at t=0, and for the last 3 meters happens at the very end of your run
    - Connect the starting speed and ending speed with a line, and find the slope for that line
    - Conclusion
    - What are the units for the slope you found in the analysis?
    - What does the slope of this graph represent?
    - Compare the slope to the acceleration you found. Explain any relationship you find.