GED Science TestPhysical ScienceEasy
A student is conducting an experiment to determine how the temperature of water affects the rate at which a sugar cube dissolves. They use three beakers, each containing 100 mL of water at different temperatures: 20°C, 40°C, and 60°C. They add one sugar cube of identical size to each beaker and record the time it takes for each cube to fully dissolve. Which of the following is the independent variable in this experiment?
- AThe size of the sugar cube.
- BThe volume of water in each beaker.
- CThe temperature of the water.
- DThe time it takes for the sugar cube to dissolve.
Show answer & explanationAnswer & explanation
Correct answer: C. The temperature of the water.
The independent variable is the factor that is intentionally changed by the experimenter. In this scenario, the student is varying the temperature of the water to observe its effect.
Why the other options are wrong
- A. The size of the sugar cube is a controlled variable, kept constant to ensure a fair test.
- B. The volume of water is a controlled variable, kept constant to ensure a fair test.
- D. This is the dependent variable, as its value is observed and measured in response to changes in the independent variable.
Independent Variable
The variable in an experiment that is intentionally changed or manipulated by the researcher to observe its effect on another variable.
- It is the 'cause' in a cause-and-effect relationship.
- It is controlled by the experimenter.
- Usually plotted on the x-axis of a graph.
Memory trick: IV is what I Vary; DV is what I Discover.