Rubber Band Car. Tommy Stewart Corey Marineau John Martinez

Transcription

1 Tommy Stewart Corey Marineau John Martinez Rubber Band Car PURPOSE: Create a rubber band propelled car that will travel three meters. Then create a regression line using the data that represents how the car traveled. MATERIALS: K-nex pieces: 24 green rods 12 white rods 24 blue rods 7 yellow rods 1 grey rod 6 dark grey connectors 1 light grey connector 9 orange connectors 12 red connectors 1 green connector 5 yellow connectors 14 purple connectors 6 blue connectors 2 blue washers 2 grey washers 6 tan connectors/wheel lockers 2 large wheels with rubber 2 small wheels with rubber 2 rubber bands PROCEDURE: 1. Determine the material to build the car with. 2. Find the K-nex that are needed. 3. Build car out of K-nex pieces. 4. Modify car to run on rubber bands. 5. Test car on the test track in the cafeteria.

2 DISCUSSION: We used different polynomials to graph the travel of our car and to predict the maximum velocity and acceleration that the car achieved. We did this by deriving the different functions and finding where the lines crossed the x-axis. After all of the math was tabulated it turned out the graph we arrived at was very close to the actual results that we achieved in our experiment. Test 1 Test 2 Test 3 Average Rubber Band Car Data Set 1.45s.83s 1.29s 1.81s 2.54s 2.09s.4s.86s 1.28s 1.62s 2.3s 3.7s.5s.77s 1.16s 1.68s 2.05s 1.84s.45s.82s 1.24s 1.7s 2.3s 2.54s Rubber Band Car Data Set 2 Distance Traveled Time Traveled Within Velocity (m/s) Within Track (m) Track Test Test Test Average Discussion: Quartic Regression line: a= b= c= d= e= R^2= Series 1 f(x)= *x^ *x^ *x^ *x ; R²=0.9994

3 Velocity function: Velocity Points:.5/.45= /.37= /.42= /.46= /.5=1.5/.24= Series 3 f(x)= *x^ *x^ *x^ *x+0.078; R²= Acceleration: Series 3 f(x)= *x^ *x^ *x

4 REFLECTION: This project showed us the point of taking the derivative of a function. The first derivative is to find the velocity function. When this function is found, any number can be plugged into the equation to find the velocity at that point in time. The second derivative is used to find the acceleration of the function. This acceleration equation can either be a constant or a function. I enjoyed this project because it involved constructing a car while learning the real life use for derivatives. I would recommend this project for next year s students because up to this point I did not get the real life use for derivatives. The one thing that our group found frustrating was figuring out a way for the rubber bands not to get caught when launching the car. This was a great, enjoyable project. EVALUATION PHASE: 1. Did you succeed in creating a rubber band car that traveled in a straight line for 3 meters within the track? If so, how far did it travel? If not, why did it fail? Our rubber band car did complete the task of traveling 3 meters within the track. Our car traveled 3.45 meters on average. 2. What is the maximum velocity your car achieved? a. Find regression with value closest to one: b. Find derivative using power rule: Velocity function= 2 c. Find derivative using power rule again: Acceleration function= d. Set acceleration function equal to zero (solve with calculator): Maximum velocity occurred at seconds 3. Did you have to revise your original plans? Yes we had to make minor changes to the car to make it travel the 3 meters needed. We adjusted the places that the rubber bands attached to make them strong enough to keep tension in the rubber band without breaking. We also changed the resistance at the axels to make them rotate better. 4. If you had access to materials that were different than those provided, what would your team have requested and why? Luckily, we did have access to better materials such as K-nex for this project so we do not have any requests for better materials.

5 5. What designs or methods did you see other teams try that you thought worked well? I thought the design Luke s group came up with was very good, it was sturdy and went the distance consistently. I thought their usage of Legos was a very good idea because it made a stronger car then most groups were able to come up with. 6. Do you think you would have been able to complete this project easier if you were working alone? Explain I think that this project would have been equally difficult if we had done it alone but while the difficulty would have stayed the same the fun level would have been a lot lower. This project was very fun because we got to work as a group and play with K-nex.