2010 Pumpkin Drop Rules  

On Thursday October 28, from 12:30 to 1:30, the Society of Physics students will drop pumpkins from the top of the Batten Arts and Letters building (BAL) (10 stories up or about 100 feet). Build a (stand-alone) device to catch a pumpkin without damaging it. Answer some questions explaining the physics of the drop and the catcher. You can earn extra credit (equivalent to one HW problem set) for PHYS101 (depending on the quality of the pumpkin catcher and how well you answer the questions). Teams of up to four (students or others) can participate; however, every member of the team must submit their own, independent solution to the questions. Any number of teams can participate. You can use the Physics Forum in WebAssign to look for team mates and get organized. I've set up a new topic for this purpose. Just go to the link "PHYS101 Class Forum" under "Communication".

Important:

  1. Deadlines are looming! You must register with Dr. Kuhn skuhn@odu.edu (send all names and UINs of all students that plan to participate with your group - up to four!) and with the SPS (I can do this for you, but it is better if you contact them directly: swood055@odu.edu or czabr001@odu.edu) by next Monday, October 25!
  2. You must buy 3 pumpkins (normal size) for your group and drop them off at the SPS office (Room 136) or the Physics Shop ( Room 124; both on the long narrow hallway on the ground floor of the OCNPS class room building) by next Tuesday, October 26.
  3. You and your team must arrive at the site, with your catcher ready to be moved into place, by 12 noon on next Thursday, October 28. Make sure one of you contacts me when you see me there!
  4. Your personal answers to the Problems below must be handed to me by Thursday, November 11 at the latest (2 weeks after the drop), in class.

Pumpkin Drop Rules:

  1. Register your team entry with Dr. Kuhn (skuhn@odu.edu) (for extra credit) and with SPS  in person or by email to swood055@odu.edu or czabr001@odu.edu  by Oct 25.
  2. Your pumpkin catcher should be 3 feet by 3 feet in size or larger so that the pumpkin droppers can hit it from 10 stories up.  (2.5 feet square is probably OK but anything smaller will probably not be hit.)
  3. Bring 3 pumpkins (each about 8 to 10 pounds) to the Society of Physics Students office, Room 136 OCNPS, (or to the Physics Shop, Room 124 OCNPS) by 10:00 AM on Tuesday 10/26.  Note that they cannot guarantee that your specific pumpkins will be dropped on your catcher.
  4. You will be able to set up your catcher about 15 feet from the drop point. Your pumpkin catcher needs to be able to be quickly (1 to 2 minutes) moved into position and quickly removed afterwards. Nobody will be allowed near the catcher during the drop!
  5. Your team may consist of up to 4 people. Not everyone needs to be present at the drop, but enough members of the team must be present to move the catcher in and out, and at least one member must be there by 12 noon.
  6. No styrofoam peanuts allowed.  They are too hard to clean up. Forget about using water - it's too heavy and you won't have time to "fill".
  7. Bring your pumpkin catcher to BAL by 12:00 noon on Drop Day.
  8. Answer some questions explaining the physics of the drop and the catcher - see below. Write your answers on a sheet of paper, put your name and UIN on it and turn it in to me (S. Kuhn)
Pumpkin Problems (due in class by Thursday 11/11 - EVERY participant must turn in a sheet of paper with the answers to these questions, your name and UIN, and a list of all members of YOUR team if you want to get the extra credit!):
  1. What is the force of gravity (in N) on a 9 pound pumpkin?
  2. What is its potential energy relative to ground at the top (30 m up) of BAL (in J)?
  3. What is its kinetic energy the instant before it hits your pumpkin catcher (in J)?
  4. How much work does your pumpkin catcher have to do to stop it (in J)? [Hint: What is its kinetic energy after it has been stopped? How much did the catcher change the pumpkin's kinetic energy? Make sure you get the sign right!]
  5. How tall is your pumpkin catcher (its height from bottom to top in m)?
  6. How much force does your pumpkin catcher exert on the pumpkin (assuming that it uses the entire height of your pumpkin catcher to decelerate the pumpkin)? [Hint: remember that Work Done = Force times Stopping Distance.]  Give your answer in Newtons.
Hints:  In the past, people have used empty milk jugs, pillows, straw, etc.  Successful pumpkin catchers have ranged in height from 2 to 10 feet tall. Here is a video taken by a camera inside a dropping pumpkin from one of the previous events.

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Last modified: Monday, Oct 25 2010.