5. Discussion and Conclusion

5.1 Key findings
There are a few significant factors affecting the speed of the car and the distance the car travels.

The weight of the car plays an important part as a lighter chassis would enable the car to have greater acceleration and therefore travel faster, going by the formula F = ma.

When the trap is pulled back, the distance between the end of the wooden bar attached to the trap (where one end of the string is) and the rear axle (the other end of the string) has to be short. Thus, when the trap is released, the wooden bar is able to pull the string a further distance.

Similarly, when the trap is at rest, the distance between the end of the wooden bar attached to the trap (where one end of the string is) and the rear axle (the other end of the string) should be relatively long, such that the string is pulled a further distance when the trap is released after being pulled back, allowing the car to travel longer, and therefore achieving greater distance travelled.

To increase friction between the wheels and the ground so as to prevent slipping, which would ultimately cause the car to not travel far, duct tape was stuck around the rims of the wheels.



5.2 Comparisons with other designs based on research
Compared to other designs, the wooden bar we used was not ideal, as it was slightly flexible and relatively short compared to other designs with more firm and longer bars used. These factors reduced the efficiency of the wooden rod and ultimately the entire system enabling the car to function. The chassis was made out of wooden sticks glued together, which affects the reliability of the chassis in holding the main components of the car (i.e. mousetrap).

5.3 Evaluation of Engineering Goals

In our car, the Mousetrap was used as the only energy source to propel the car forward. Our car also met the requirements of the maximum length of 30cm, width of 10cm, and a height of 10cm. However, it could not travel a distance of 5 meters.

5.4 Areas for improvement
We could have used lesser ice cream sticks to decrease the unnecessary mass, because when the 'm' in a = f/m decreases the acceleration will increase, making the car go at a faster speed. Furthermore, we could have used a bigger back wheel so that we could have more distance covered in one turn of the axel. Another area for improvement is the stopper used to fit the axle into the CD. We could use sink washers rather than styrofoam as they are softer and will not cause the car to stop abruptly.

5.5 Practical Applications

The Engineering Design Process (EDP) used in our project
- helps us think out of the box to come up with unique designs and ways to do it
- makes us think about formula's we've learnt in school to make the best design for our car but to still let our creativity flow and think of different ways we can tweak it and make it better
- develops skills such as problem solving, critical thinking and cooperation
- shows the importance of picking the correct materials to maximise the efficiency of the car

5.6 Areas for further study
We could investigate different types of materials used to build the different components of the car and find out what the best combination of materials is that allows the car to have greatest efficiency in travelling. For example, what the best type of anti-slip/friction-increasing material to use on the wheels would be, or what to use as a connector (string) between the trap/wooden bar and the rear axle such that it creates more force to power the car forward.

5.7 Bibliography

Brad & Tiffanie. (n.d.). Guide to Mousetrap Cars. Retrieved Mar 24, 
2014, from 
http://engineeringed.usu.edu/Projects/MousetrapCars/Mousetrap%20
Cars.pdf

Gelo, T. (07 Apr 2006). Mouse Trap Cars. Retrieved Mar 22, 2014, 

Hansel, P. S. (n.d.). How to Adapt a Mousetrap Car for Distance. Retrieved Mar 23, 2014, from http://www.wikihow.com/Adapt-a-Mousetrap-Car-for-Distance

McCoy, K. (31 July 2010).  Mousetrap Cars. Retrieved Mar 24, 2014, from http://mesa.ucop.edu/staff/masme_2010/WORKSHOPS/Mousetrap_Madness/Mousetrap_Car.pdf

Mousetrap Car. (n.d.). Retrieved Mar 23, 2014, from Wikipedia: http://en.wikipedia.org/wiki/Mousetrap_car




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