Purpose:
This lab is the culmination of our bungee jumping lab. This lab revolves around the work-energy theorem. You will use your knowledge and understanding of energy to calculate the maximum mass you can drop off the railing in the Science Building (used to be outside the Fireside Room in Grandview) without damaging the floor below. (Missing the target doesn't count!)
COVID 2021:
This lab usually depends on having access to all the equipment and the railing over the lobby of the Science Building. For remote teaching the data is provided to you in this python notebook called BungeeDropLab.ipynb. The deliverables for this remote version of the lab are in the notebook.
Procedure:
For this lab you will need the bungee cord data sheet, your calculators, some lab weights, and your minds.
- 1) Examine the cord and the site carefully so you understand the experimental setting. Ask questions! The measured height of the railing is unknown at this point. Calculate how far the bungee cord much stretch if the mass will just touch the floor. There are several stages to this bungee jumping process and it is easy to confuse yourself. This would be a good time to start building your energy bar chart.
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2) The bungee cord we are working with is a little older than the cords we originally used for the first lab. Work out a method for checking the calibration of the longer bungee cord we will use today.
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3) Figure out how much energy will be absorbed by the bungee when it has stretched to the floor. There are a number of possible methods you might use and you should check with your instructor before diving in too deep. I recommend that at least two people in each group determine this energy independently to try and catch any errors.
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4) Once you understand the energy situation you can then calculate the maximum mass you can put in the bag so that when it is pushed off the railing it will just hit the "floor" without breaking it. When you have completed your calculation assemble the mass in a stack on the front lab table.
5) We will then take the bungee cord to the railing and test your calculations.
LAB REPORT:
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I) Describe the task you have been posed along with the pertinent details of the apparatus and site.
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II) Describe the process and results by which we verified and/or modified the force curve for the bungee cord.
III) Present the proceess and calculations that support your solution for the mass. This section should clearly indicate how you arrived at the mass that could be dropped without damaging the floor. All solutions must include an energy bar chart that indicates where the energy is at the begining, middle (no energy in bungee), and bottom of the process.
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IV) Briefly discuss the success or failure of your calculation. Analyze the process by which you calculated the mass and identify the most critical element of the process. This is your opportunity to show your understanding of the factors which make this a non-ideal experiment.
Bungee Force Plot (gif)