Student designed investigation
You have just started working at a pencil factory and your boss shows you into a room where a large pile of pencils has been left. The pencils are of varying hardness and unfortunately they have not been labelled yet as the labeling machine broke down. Your new boss tells you that you have to sort through them all and group them into pencil types from hard 5H, 2H, etc. to HB to soft, B, 2B, 6B. Luckily for you they were made from the same machine so the graphite leads are all the same width and length.
Thankfully you are a student of physics and can use your canny knowledge of resistivity to solve this problem!
In this task you will investigate the resistivity of graphite pencils. You will have to design an experiment that will produce enough evidence to predict how the resistivity relates to the hardness. You will have to collect enough data to give a reliable statement about the resistivity of the pencils you investigate and to create a table that can be used to test the unknown pencils accurately. You will have one double lesson to gather your results so it is important to plan your experiment before hand.Designing an experiment
Planning
You should work in groups of 2-3 to develop your method and then run your experiment
Assessment Rubric