“The Over Elaborate Egg Destroyer”
Introduction: When given the opportunity to design and construct a device for no reason other than to do it, we decided to do the obvious- break eggs! We used gravitational potential energy to power a ball going through a miniature obstacle coarse to smash the doomed egg lying below. Of course it would have been simpler to have just crushed it by hand, but we would not be engineers if we did something as simple or with such common sense would we?
Design process: We met up and brainstormed what we wanted to do. Matt envisioned the obvious choice was to break an egg; none of us protested. We made calculations to determine a rough estimate on what was needed to break the egg, and then Matt came up with a basic idea of the building plans. We then met up and used his designs to build the contraption after a few changes during the construction process.
Construction Process: We first tried to use the basic design we created, but quickly found out that some things were not going to work the way we envisioned. We started to build the egg destroyer by first building the 6 vertical bases which would hold up the PVC pipes and the plastic swing. This took sawing, sanding, and nailing the wooden bases into the ground base. From there we were able to get a better understanding of where to put the pipes and at what angles they would be. We screwed in wooden blocks between the middle vertical base to hold the pipes in place and from there we built the plastic from where the pipes lined up. We also screwed in the bases so they would fold
keeping it more portable when in storage. The finished project was definitely altered from the original plan as Kyle had to make it logistically possible to construct, but overall the basic idea of the steps stayed the same.
Calculations and Measurements: The top pipe is 37 inches. The bottom board from the
point where the end boards stick up is 37.2 inches. The bottom pipe is 38 inches. The change in height the first golf ball goes through before it hits the spinner is 10.5 inches. When it collides, it is a perfectly inelastic collision. The spinner then makes contact with another golf ball in an elastic collision. The second golf ball then goes through a height change of 16.5 inches before hitting the egg at the end. The diameters of the golf balls are 1.75 inches. The weights of the golf balls are each 1.6 ounces and the weight of the spinner is 10.5 ounces while being 6.6 inches long. The first calculation we did was the conversion of gravitational potential energy of the first ball into kinetic energy from the top until it hits the spinner. The conversion process proceeds as followed. 2.5mv=mgh .5v=(2gh) .5v=(2*32.2 ft/s*10.5in)
Above shows the final velocity of the first ball before it hits the spinner. The second calculation we did is the perfectly inelastic collision of the first golf ball colliding with the plastic spinner, which would give us the velocity of the spinner when it hits the second ball. That formula is:
Now having the velocity of the spinner we were able to find what would be the initial ndndvelocity of the 2 ball as it enters the 2 PVC pipe. The spinner stops after making
contact with the ball and the ball starts from rest. That formula is:
mv+mv= mv’+mv’ ballballspinnerspinnerballballspinnerspinner
Knowing the initial velocity we then had one last calculation to make, the final speed of the ball after it comes out of the tube and makes contact with the egg. That formula is: 22.5mv’=mgh+.5mv 2.5v’=(2gh+v) 2.5v’=(2*32.2ft/s*16.5in+(6.043ft/s))
This is the final velocity of the second ball as it strikes the egg.
Cost of Materials: The supplies came to a total of $11.47. The PVC pipe was the most expensive material. It accounted for $8.26. The wood only cost $3.21 while the screws we used were Kyle’s and the eggs shattered were Matt’s.
Conclusion: Our team was successfully able to design and construct a Rude Goldberg style device that would crack an egg. We took a basic design at first and applied the engineering techniques we’ve learned throughout the semester to further improve and make the device logistically possible and the finished product came out easy to use while accomplishing its goal.
(The Egg Destroyer)