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Homework Help: Egg Drop Design Help

  1. May 22, 2009 #1
    Egg Drop Design Help!!!

    1. Ok, I need some ideas for an egg drop project in my class.
    A. Dropping from 7 Ft, then 12 Ft, and then 25 Ft... Consecutively.
    B. Can't be more then a Meter in height.
    C. Allowed to use the following:
    1. 15 Popsicle Sticks
    2. 15 Straws
    3. 5 Rubber Bands
    4. 100cm of String
    5. 100cm of scotch tape
    6. Rubber Cement (Only as an Adhesive)
    7. And of course an egg.

    2. Gravity Accelerates at 9.8 feet/second

    3. I've tried almost everything I could think of and tested it off my house's 20 foot balcony... Nothing I've tried works and I'm really hard pressed for time. So any ideas?
  2. jcsd
  3. May 22, 2009 #2


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    Staff: Mentor

    Re: Egg Drop Design Help!!!

    Actually, the acceleration due to gravity is 9.8 feet/second^2

    Welcome to the PF. Take a look at the related threads listed at the bottom of the page. Then you can also do a Search (use the link at the top of the page) for other threads with Egg in the title. All of those threads should start to give you some ideas.
  4. May 22, 2009 #3


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    Science Advisor

    Re: Egg Drop Design Help!!!

    Here's what I would do:

    1. Arrange popsicle (I'm guessing all of them) such that they enclose the egg, aligned with the axis of the egg. Rubber cement together so it makes a tight fit with the egg; tape around.

    2. While you're putting the sticks together, cut a rubber band apart and "lock" two pieces of it inside the sticks such that they make an X at the bottom of the sticks.

    3. So the same thing with the straws but outside of the sticks. Put the rubber bands an inch or so up from the bottom of the straw.

    3a. The idea is that when the container hits, the outside straw container will stop, and the popsicle stick container inside will slow against the straws' rubber bands, meanwhile the egg will be slowing against the rubber bands below it. Add only enough rubber bands such that the objects won't fall past the bottom during impact. You want to keep it soft.

    4. With the remaining materials I add a fan-type propeller at the top to ensure it falls straight down.

    5. If there are any straws left, I do my best to make a spring at the bottom to further soften the fall.

    That design should be easily droppable from 40+ ft.
  5. May 22, 2009 #4
    Re: Egg Drop Design Help!!!

    Hi, sorry this doesn't relate to the materials you have but I thought you might be interested anyway.

    The best idea would be to slow the rate at which the egg stops as minger has described.

    Acceleration due to gravity is 9.8m/s2
    Last edited by a moderator: Sep 25, 2014
  6. May 22, 2009 #5
    Re: Egg Drop Design Help!!!

    Actually, the acceleration due to gravity on planet Earth is 32.2 ft/s/s., which is equal to 9.8 m/s/s.
    If the acceleration of gravity specified is indeed 9.8 ft/s/s, then the equivalent dropping heights to get the same impact speed as 7,12 and 25 ft are 2.13, 3.66 and 7.62 feet respectively... if the tests are to be done on planet Earth.
  7. May 22, 2009 #6
    Re: Egg Drop Design Help!!!

    Are quail eggs available in your city? They are much smaller and weigh much less than the 60 gram eggs in the supermarkets.

    Also, one of the uses of the scotch tape could be for prestressing the egg shell.

    The shell is made of a material that does not stand up to tension and punching (shear). However, in pure compression, it is a relatively strong material. If you wrap the egg in scotch tape while applying some tension on the tape, then the shell will be put into compression. This process is called prestressing, a technique similar to the production of long span concrete girders used for bridges and highways. The prestressing must be done as uniformly as possible. If you don't have use for the whole metre of scotch tape, that would be a very valuable investment.
  8. May 28, 2009 #7
    Re: Egg Drop Design Help!!!

    ever thought of injecting your egg with the cement? of course it's cheating but tape the thing up and no one will know... until they break your egg to check it. i would make an assembly that suspends the egg with the rubber bands within a "chassis" that you construct from the popsicle sticks. try and use hot dog stick if you can ;)
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