Egg Bungee Jump Regression - Based on a lab by Dr. H Hirst. Work in a group of 4, but each person should fill this sheet out.

Introduction Bungee jumping looks pretty exciting. Today we will let you decide how long to make the bungee cord for a fragile jumper -- a raw egg. The goal is to make it exciting but not fatal for your jumper. A small prize will be given to the group that gets closest to the ground without harming their egg. There is only 1 egg per group.

    The Experimental Stage Gather your data as follows:
  1. Make 3 jumps each with 2, 3, 4, and 5 rubber bands from a height of 1 meter. You may wish to use a pen, and hold it perpendicular to the top of the stick, so that you drop the egg sufficiently far away from the meter stick. Record how far the egg travels from the top of the meter stick to the point closest to the ground (12 data points). Be very careful with your egg - protect it from hitting anything and make sure that it doesn't swing back and hit the meter stick. Accuracy is important, so the same person should drop the egg each time, and the same person should be watching the meter stick each trial.

    Number of rubber bands

    Distance dropped in centimeters

    2

     

    2

     

    2

     

    3

     

    3

     

    3

     

    4

     

    4

     

    4

     

    5

     

    5

     

    5

     

    		 
    Excel and Data Analysis Enter your data into excel, create a scatterplot chart and add a trendline and r2 value to it (see the other lab for directions if you've forgotten). Write down your results here
  2. REGRESSION LINE:                                                                    R2 VALUE:

  3. For Discussion (Leave Until Later) Even with the variability in rubber bands and possible measurement inconsistencies, using the r2 value, your number of rubber bands should be a very strong predictor of the distance traveled. Explain how common sense alone applied to the stretch ability and similarity of the rubber bands and the problem setup can be used to explain why the relationship is linear (ie why is it a constant slope when change in y/change x = change in distance dropped / change in rubber bands?) and why this predictor is so strong.







  4. EXACTLY what prediction of the distance traveled does the regression line give for 10 rubber bands? SHOW WORK!




  5. EXACTLY what prediction of the number of rubber bands required for 2.0 meters does the equation of the regression line give? SHOW WORK!




  6. For Discussion (Leave Until Later) Why won't everyone in the class have the same answer for this question? Relate your response to the placement of the paperclip, the weight of the egg, the egg dropper, etc.





  7. Using the predicted number of rubber bands, the R2 value, and anything else you want to factor into your decision, decide how many rubber bands you will use for the 2.0 meter bungee jump. You may be creative and fold a rubber band in half. How many will you use?


    The Contest - Directions

  8. Build, but DO NOT TEST the bungee machine, adding the rubber bands until you reach the number of rubber bands that you previously decided on, and then leave it alone in a safe place until we come back together as a class. I.e. DO NOT measure the length of the assembled bungee cord in any way, and DO NOT change or test your apparatus at all.
  9. While waiting for the contest, go back and work on the "For Discussion" or other homework for tomorrow or Thursday (see the main web page).
  10. When it is your group's turn, bring your bungee machine up to the front of the room. Perform the jump. The team that comes closest to the ground without any egg damage wins.