Question

A group of students is investigating whether silver is a better thermal conductor than copper. The students take a silver wire and a copper wire of the same length and diameter. They put equal lengths of wax on one end of each wire and dip the other end into a beaker of hot water. The length of wax left on the wires after 10 minutes is shown. Experimental Observations Silver Copper Original length of wax 3.5 cm 3.5 cm Length of wax after 10 minutes 1.2 cm 2 cm What was a control variable in this experiment?

Answer 1

The length of the two wires

Step-by-step explanation:

A control variable is what you keep the same through the whole experiment so therefore it could be both length and diameter

Answer 2

The control variable in this experiment is the original length of wax 3.5 cm applied to both the silver and copper wires.

A control variable is described as an element of an experiment that remains constant across all test groups which allows you to isolate the effect of the independent variable on the dependent variable.

In the experiment, the students kept the original length of wax the same for both wire which ensures that any difference in the amount of wax melted after 10 minutes is due to the differing thermal conductivity of silver and copper, not because of variations in the initial wax amount.

Variables like the temperature of the water and the diameter of the wires, were also likely kept constant to further minimize the influence of factors other than the wire material.

In conclusion, we can say that by controlling the initial wax length, the students created a fair comparison between the thermal conductivities of silver and copper, allowing them to draw valid conclusions from their experiment.