5. Discussion and Conclusion

5.1 Key findings

Force = Mass x Acceleration. According to this equation, when given a mousetrap that applies a constant force, you will have to reduce the mass as much as possible in order to maximise acceleration in order to travel the 10 metres that we are tasked to do.

Turning Force (Torque/Moment) = Force Applied x Distance between Line of Action of Force and Pivot. In order to maximise turning force to speed ratio, we have to find the appropriate Distance between Line of Action of Force and Pivot in order to balance the resultant force applied to turn the wheel and also torque to turn the wheels.

Inertia is the tendency of an object to resist a change of state of motion. This happens all the time. When a car is moving fast, the inertia will cause it to travel further than a car traveling at a slower speed, causing it to cover a greater distance compared to the car moving at a slower speed.

5.2 Comparisons with other designs based on research

Other designs are better than our design due to the fact that they maximised acceleration by reducing the mass of the car as much as possible. This will give them an edge over us due to their increase in acceleration that will guarantee more distance travelled by other cars.

Another disadvantage that we had is that the the ratio between the diameter of our axle and the diameter of the CD is lower than some of the other groups. This will cause the moment applied minus the moment required to move the car to be lesser, resultant in a lower force applied which causes our car to loose speed compared to other cars.

5.3 Evaluation of engineering goals

(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

Height exceeded to 15cm, width and length within size.

(c) Can travel a minimum distance of 5 meters carrying an egg (the egg will be

provided by the teacher)


5.4 Areas for improvement

We could have made sure that we minimise the mass of the car in order to have a greater acceleration in order to have enough inertia to finish the 10 metre course that is tasked to us to do.
Furthermore, we could have also used a direct connect of a string to the axle of the wheel, rather than using gearing. This is because, gearing cause friction which prevents the inertia of the car from moving the car forward after the string has run out.
5.5 Practical Applications

We can apply F = MA when we are tasked to create something that travels far with a constant amount of force applied by minimising the amount of mass the vehicle has inorder to travel further. We can also apply things we learnt about the turning effect of forces to real life when dealing with gear ratios. When assembling something that involves gear ratios, we have to ensure that we balance speed and torque required to turn the wheels without stalling the motors.

5.6 Areas for further study
We can research further on how we can improve on our design in terms of the mass. One major problem in our mousetrap car was that it was too heavy and therefore was unable to travel the requirement of 8m. Therefore, we need to research for a better choice of material that would help cut down on the mass and allow the car to travel farther according to the formula F/m=a.

5.7 Bibliography
[1] http://www.wikihow.com/Adapt-a-Mousetrap-Car-for-Distance
[2] http://en.wikipedia.org/wiki/Moment_of_inertia
[3] http://science.howstuffworks.com/wheel-and-axle-info.htm

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