Don't Drop The Eggs

... unless you are instructed to do so by your physics teacher

My fellow blogger, zlessard, has also just posted a blog about a similar topic, as we both had to write one up for class. Our mistakes were different but we both had the same goal.

The purpose of this lab was to figure out what height the arm on which the rubber band and egg were attached had to be so the bottom of the egg just touched the top of the paper (resting on a table) below it. To find out what height it needed to be, the potential energy of the system had to be determined. Potential Energy (U)= mass (m)*Acceleration due to gravity(g)*height (h). Once potential energy was found, it would be possible to determine the height, since the mass of the egg was known. To find the potential energy stored different masses were used to determine a different displacement of the rubber band as well as the force applied. On earth we know the acceleration due to gravity is 9.81 m/s^2 so the force applied is easy to find (F=ma). When the different masses were added to the rubber band the displacement was able to be found by measuring how far the rubber band. The area under a force vs. displacement graph is equal to potential energy. This is where my group messed up. Instead of integrating by weight, we integrated by mass. This would give us the wrong value for the potential energy causing the rest of the calculations made to find the height at which to drop the egg from. So after integration, you find the potential energy to be .8932J. Then using the equation U=mgh, you can figure out the height, which in our case would be 1.3007m since our egg had a mass of .07kg and the acceleration due to gravity on earth is 9.81 m/s^2. Yesterday, when we dropped our egg we were lucky enough to make an educated guess that was correct. At least, my group has discovered our mistake (integration... it's important) and can move forward with this knowledge. 

I highly suggest trying this at home (be prepared to clean up and broken eggs!!!) because it's a great lab to do for fun. Even if you do trial and error drops  

You'll need a few rubber bands, a place to attach the rubber band to. And then something to attach the rubber band to the egg. Good luck!