A group of students is investigating whether copper is a better thermal conductor than steel. The students take a copper wire and a steel 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
Copper Steel
Original length of wax 3 cm 3 cm
Length of wax after 10 minutes 0.7 cm 1.8 cm
What was the dependent variable in this experiment?
a) Type of wire used
b) Original length of wire
c) Original length of wax
d) Thermal conductivity of wire
d) Thermal conductivity of wire
The dependent variable in this experiment is the length of wax remaining on the wires after 10 minutes. To determine the dependent variable, you need to look at what aspect of the experiment is being measured or observed. In this case, the students are investigating whether copper is a better thermal conductor than steel. To do this, they measure the amount of wax that has melted after 10 minutes on both the copper wire and the steel wire. The difference in the lengths of wax remaining on the wires is what is being measured, making it the dependent variable.
Therefore, the correct answer is:
d) Thermal conductivity of wire.
The dependent variable in this experiment is:
d) Thermal conductivity of wire