Sample Solution

For the investigation I connected the electrical motor to a VariVolt power supply. The power supply was set at a constant 8 volts throughout the entire data collection process. To the motor, the brake disk was attached through the use of a pulley system. The motor and the wheel of the model brake disc were connected with a large (and wide) rubber band, as conventional rubber bands would break very quickly, and therefore cause random error throughout the data collection (this was established through a preliminary test of the setup). The motor was then turned on for 60 seconds, to allow the disc to accelerate to a terminal velocity. After exactly one minute, the mass was dropped onto the spinning disc from a height of 0.01 meters. The acceleration due to the drop will affect the system to a negligible amount. Then the time taken until the disc comes to a stand-still was measured. At the same moment, when the mass was dropped onto the model brake disc, the power supply for the motor was stopped, allowing the model to spin as freely as possible, and be affected by as little resistance as possible. In addition to this, the change in the temperature of the spinning disc was recorded with an infrared thermometer a set distance away from the model. The initial temperature was measure off of the spinning disc immediately before the masses were dropped onto it, the final temperature was measured when the disc had just come to a halt. The time taken until the disc comes to a stop, as well as the increase in temperature was then recorded in a Microsoft excel spreadsheet. For each different mass I recorded 5 trails to take the average from, as the process of data collection may well result in random error.

Preliminary research
With the same setup as described in the method, I conducted a preliminary test, in which I found out that due to the increase fatigue on conventional rubber bands, the braking times would decr