Science Buddies: "Ask an Expert"

We are doing the Hydropower Lift a load experiment. We are listing the independent variables as the amount of water being used from the faucet and the speed of which the water is dropped (flow rate). The teacher said this was incorrect.

Also, we said the dependent variables are the time it takes to wind up the weight and the speed at which the waterwheel turns. Teacher said this was incorrect.

Please let me know what the independent and dependent variables should be. Thanks. AC

If you haven't done so, you should read the Scibuddies explanation of experimental variables: https://www.sciencebuddies.org/science- ... bles.shtml

"The independent variable is the one that is changed by the scientist. To ensure a fair test, a good experiment has only one independent variable. As the scientist changes the independent variable, he or she observes what happens.

The scientist focuses his or her observations on the dependent variable to see how it responds to the change made to the independent variable. The new value of the dependent variable is caused by and depends on the value of the independent variable."

In the hydropower project, the variable that you control and change is the flow rate of the water that hits the water wheel, so that is your independent variable. The dependent variable that changes in response to the flow rate is the speed that the water wheel turns and thus how fast the string is wound up.

thank you very much.