2.2 Construction of Prototype, Testing & Modifications

2.1 Construction of Prototype


Mass of mousetrap car
368g
Mass of each wheel
19g
Wheel diameter
2.3cm
Axle diameter
0.9cm
Length of spring (end of lever to axle)dccd
39.3cm
Length of lever extension
18.0cm
Overall length
27.3cm
Overall width
16.9cm
Overall height
9.4cm

Insert photographs of prototype: 


- Front and back view



- Side view



- Top and bottom view


2.2 Testing and Modification





Run no.
1


Total time of test run / s



Total Distance of test run / m
0.75


Was the car in steady and stable motion throughout?
Yes


Was the car moving in a straight line mostly?
Yes


Did lever and string operate smoothly as well as expected?
Yes


State one area of modification
Reduce friction between the ground and the front and back wheels (toy car tyres) by using thinner wheels instead (CDs)


State rationale(s) for the above-proposed modifications.
The car was unable to travel a longer distance due to too much friction and hence it slowed down faster. By using CDs, which are much thinner than toy car tyres, the friction between the ground and the wheels will be reduced and the car can travel further.




Run no.
2


Total time of test run / s
0.0


Total Distance of test run / m
0.0


Was the car in steady and stable motion throughout?
No. The car did not move at all.


Was the car moving in a straight line mostly?
No. The car did not move at all.


Did lever and string operate smoothly as well as expected?
No. The string had too much tension and friction resulting in the car not moving at all. The traction between the wheels (CDs for back wheels, toy car tyres for front wheels) and the ground was not enough to drive the car forward.


State one area of modification
Add rubber coating on the edge of the wheels (CDs).
Add an additional piece of cardboard to hold the axle for the back wheels in place.


State rationale(s) for the above-proposed modifications.
Rubber coating will provide for more traction between the wheels and the ground.
The additional piece of cardboard used to hold the axle of the back wheels in place will allow the tension in the string to be released. Previously, the tension in the string could not be released because we only used one piece of cardboard, resulting the the axle of the back wheel turning sideways, preventing the car from moving.





No comments:

Post a Comment