A student investigated how the number of layers of cotton fabric wrapping a cylindrical solid brass block affects the rate of thermal energy transfer to the surroundings. The student's results are shown in the graph below.
a.[6]
Describe a method the student could have used to obtain the results shown in the graph.
b.[2]
The student considered using a temperature probe connected to a digital datalogger instead of a digital thermometer. Both instruments display readings to one decimal place (e.g., 85.3 ∘C85.3\text{ }^\circ\text{C}85.3 ∘C). The datalogger is set to record 15 readings per second. Explain why it was not necessary to use a temperature probe and datalogger in this investigation.