A group of students is investigating whether copper is a better thermal conductor than aluminum. The students take a copper wire and an aluminum wire of the same length and diameter. They put equal lengths of wax on one end of each wire and dip the other ends into a beaker of hot water. The length of wax left on the wires after 10 minutes is shown.



Experimental Observations

Copper Aluminum

Original length of wax 2 cm 2 cm

Length of wax after 10 minutes 0.7 cm 1.2 cm



What was the independent variable in this experiment?

Final length of wax

Type of wire used

Original length of wires

Thermal conductivity of wire