5 Discussion and Conclusions
5.1 Key findings
Our key findings are that there are significant factors affecting the speed of the car and the distance it travels. Factors such as weight, friction between surface of wheels and ground, and wheel to axle ratio, as elaborated in the following.
5.2 Comparisons with other designs based on research
By comparing our design with other designs based on research, our car was not as light as others. Thus, other designs are better than our design as they reduced the mass of the car as much as possible, maximising acceleration. This will give the other cars an edge over ours due to their increase in acceleration that will guarantee more distance travelled.
The wheels used on the designs based on research and the wheels used on our design are also of different sizes. Most designs made used of discs for wheels while we used toy wheels, this makes our wheel to axle ratio is lower than the other designs. Thus, we conclude that the distance that the car travels will differ due to wheel to axle ratio.
5.3 Evaluation of engineering goals
- Develop a MouseTrap Car with the following specifications:
(a) Uses only the MouseTrap provided as the only energy source
(b) Has a maximum length of 30 cm, width of 10 cm, and a height of 10 cm
(c) Can travel a minimum distance of 5 meters carrying an egg (the egg will be provided by the teacher)
(d) All time-lines have to be adhered
(a) We used only the mousetrap as the energy source.
(b) Width exceeded by 10.5cm, length of 28cm and height of 7cm within maximum.
(c) Travelled a distance of 3m, short of 2m.
(d) We adhered to all time-lines.
5.4 Areas for improvement
We could have tried to start on the car earlier and we could have secured the car properly. We could have modified the car such that it weighed even less and used different wheels such that our wheel to axle ratio would be higher. Modifications that were already made include using a thicker and longer string so that the car would travel further and the string would not snap easily, and using a longer stick with the longer string so that the car would have more energy to travel further.
5.5 Practical Applications
The mousetrap car design can be applied to the real world where real cars are designed. The rubber toy wheels in our mousetrap car design resembles the wheels of an actual car as the wheels is made of rubber. When the rubber comes into contact with the road or ground, there will be frictional force between the ground and the tyres, be it good or bad weather. The grooves in our tyres would also help to channel out water in the wheel during rainy weather.
In the future, the concept of mousetrap cars can be used to build cars powered by ‘clean energy’ using machines similar to the mousetraps in order to power cars built for humans.
5.6 Areas for further study
We could have researched for better materials to build the car such that it was even lighter, but maintaining/increasing the stability and secureness at the same time, and used wheels which had a higher wheel to axle ratio. We could also have investigated if a three-wheeler or four-wheeler was better. Would a three-wheeler be better due to it being more lightweight and aerodynamic? Also, is there a relationship between the tension in the string and the distance the mousetrap car travels?
Donald, L. S. (n.d.). Mouse Trap car. Retrieved March 14, 14, from http://www.instructables.com/id/Mouse-Trap-car/
McCoy, K. (2010, July 29). Mousetrap Cars. Retrieved March 18, 14, from http://mesa.ucop.edu/staff/masme_2010/WORKSHOPS/Mousetrap_Madness/Mousetrap_Car.pdf
Parker, A. (2011, March 22). HowStuffWorks "How Mousetrap-powered Cars Work". Retrieved March 15, 14, from http://auto.howstuffworks.com/mousetrap-powered-car.htm