Mitchell learned about convection in class. In convection, warmer fluids rise and cooler fluids sink because they have different densities. He decides to conduct a scientific investigation to measure how the density of water changes with temperature.

Mitchell measures 100 g of cold water in a graduated cylinder and measures and records its temperature and volume. He uses a microwave to heat the water slightly, measures its temperature, and measures its volume. He repeats this several times.

In this investigation, which variable is changed by the investigator?

A.

the volume of the water

B.

the phase of the water

C.

the temperature of the water

D.

the mass of the water

C. The temperature of the water is the variable changed by the investigator

Explanation:

As in the experiment, it is said that the investigator wants to see the influence of temperature on the density of water. So from the experimental procedure discussed in the problem, it is known that Mitchell, the investigator is taking 100 g of cold water and measures its temperature and volume occupied by that mass of water at different temperature. So as the heating device is used as microwave oven, then it can be indicated that the temperature of water has been modified by the investigator. Thus it can be confirmed that the variable changed by the investigator is the temperature of water by reheating the water using microwave oven.