Bungie Barbie

Set up the equipment, attaching a Barbie on a cord to the force probe.  Connect an accelerometer to Barbie and her harness. Remember that you need to tell the Logger Pro what type of force probe is attached...it may not do so automatically.  Place a motion sensor below Barbie on the ground. Determine Barbie's Fw, and F(net) and Fup Your calculations must be shown at the moment that Barbie is at the maximum extension of the rope going DOWNWARD. All calculations must be summarized in a table when you turn in the lab.

Procedures:
Produce as least 5 different graphs by dropping Barbie with different cords. Use the evidence to collect a rationale for the common use of rubber as a bungie cord, and whether it is supported by your data.


Print or save your graphs for each "jump". Clearly indicate which cord or material was used. Also include information such as the amount of force and the time over which the force was applied. Record any relevant observations you saw during the jump.  Hint (this works best if you upload each of the five files to a Google Doc folder, and then share down to your individual machine)

Calculate the Fup on Barbie and her g-force for each jump using a printed sketch of the graph and data from your trials.  This must be accompanied by a free body diagram.

Individual WRITEUP (5 to 8 paragraphs, plus tables)

• Describe the ideal harness for a bungie jumper so that net force is distributed across the barbie. This should be based on data you gathered when Barbie parachuted, your seatbelt harness, and this lab.  A picture may be helpful here.

• Explain how the total time for the Barbie to stop jumping can affect a force distribution. (Think carefully: F=ma, but a = change in velocity/change in time)

• Based on your data, is it possible to argue that there is a better material for a bungie jump than rubber? Why or why not?
• Your seatbelt lab, your parachute jump, and the bungie jump all allowed you to gather g-force acceleration data.  Create a table of g-force information and tell me which is the safest situation:  the Barbie bumper crash, the Barbie parachuting, or the Barbie Bungie jumping?   

• What do these labs tell you about extreme sports?

• What questions arose in the lab? What information have you found?