Monday, February 27, 2012

Egg drop (but not the soup)

Eggs aren't just for use in radiators.  For our latest home STEM project we made devices to protect eggs when they are dropped.  T, M and I were each limited to 100 plastic "bendy" straws, two rolls of scotch tape, two sheets of paper towel, and a plastic cup.  We bartered these items around; for example I traded my paper towels and cup for more straws and tape. 






M cut up straws into short pieces and used them as filler, like styrofoam peanuts, inside the cup.  The egg was wrapped in a paper towel in the middle.  She taped that in then lined the sides of the cup with straws against impact.


T's design used the least straws.  He used two cups and had one cut smaller and inverted inside the other.  The smaller one could compress inside the larger and create a shock absorber effect.  He wrapped the egg in a paper towel inside and had a few straws to cut and place around the outside haphazardly.


In my design the top is a 20 sided icosahedron with the egg just slightly below the center to give a "down" weighting.  I taped across the top 10 faces to act as a parachute (with a small gap at the apex to help stabilize it).  I used the remaining tape and straws to add legs at various angles to the lowest point to break the initial impact and convert the falling motion into a roll away motion.   


It unintentionally turned out looking a little like a virus particle.

 Time to test them out.  We started off with short drops of 3 feet and 5 feet onto concrete. 






No eggs were broken so we had to move to higher drops.







Everything worked at seven feet.  My virus parachuted down and rolled away.  At nine feet T's contraption flew apart on impact, but the egg was unbroken!  However, M's egg finally broke at the nine feet drop. 


After this point we had to climb onto the garage roof to get greater height over the cement.   




Tossing it off the roof at 12 feet finally broke T's egg!  The virus egg did fine.  It parachuted down at the same speed as before.

T and M are already demanding a rematch.  They have new ideas now for modifications.

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