Hands On Physics

The Great Bungee Jump
Extensions
Full Size Jump ??

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Now you have a working small scale model of a bungee jump, and a mathematical model which represents it. Now you are ready to investigate a full sized bungee jump that might be used to escape from a high rise building.

Talk with your partners and decide how tall a building to represent, how heavy a person (there are approximately 2.2 lbs/kg), how far from the ground the bungee cord should start to stretch, and how far from the ground the bungee would stretch with the person hanging on it. Enter your numbers into the mathematical model and examine the results.

Remember: You want the jumper to be slowed to a stop just at, or just above the sidewalk. (Look at the mimimum height) You also want the jumper to be lowered as gently as possible. Look at the maximum force exerted by the bungee cord. Compare this force (measured in newtons) to the force exerted by gravity (the weight of the jumper in newtons). How many times his own weight will he be subjected to? Can you make this force smaller?

When you feel you have a reasonable combination of factors which will lower the jumper safely to the sidewalk record your data. You could also print out your spreadsheet model to include with your report.

Some other things to consider are:

• How could the jumper safely disconnect from the bungee cord? What would happen to him if he didn't?
• Is the jumper in danger of smashing into the side of the building? How could you find out?
• Would it be possible to make a bungee escape device that could be used by anyone, or do they have to be custom made?