The EIT class began the afternoon by removing the wax beams they made yesterday from the molds. Using screwdrivers to chisel and pliers to yank the legos out, soon the students all had a wax beam ready to test. The students who finished with their beams first weighed bricks and cinderblocks to be used in the testing. Then the class went outside to test all the beams. Each group of two tallied the amount of weight a beam held before it broke.
The class then went inside to analyze the data. While writing the data on the board, Garrett led the class in a discussion about some possible sources of error, such as heat outside making the beams that were tested more malleable. Nonetheless, the students were able to determine that the moment of inertia of the beams made a big difference in the strength of the wax structures.
Finally, the students continued to work on the Daredevil Design Project. Garrett taught them about the important variables in the car's flight: slope when the car leaves the track and how fast it leaves. However, the students found out that velocity over such a short time is very difficult to determine: the time from departure to landing was measured to be about .35 seconds, but the error (how fast the students could react, masured by trying to make the stopwatch time equal zero) was about half that measured time. So Garrett explained that the students will use a computer program to determine the velocity based on a change in potential energy to kinetic energy. The students finished the day talking about coordinate systems which they will need to use tomorrow when finishing this project. They went to the Interactivate site and played with the maze games to familiarize themselves with the system.