A community is considering switching from coal-fired powerplants to using wind energy to generate electricity. In order todecide what type of wind turbine is best for the area, aninvestigation was conducted to compare the amount of electricitygenerated using different blade lengths. A series of wind turbineswere assembled at a location near the community and tested tocompare the amount of electricity each wind turbine could produce.Care was taken to make certain that each turbine was positioned tobe exposed to the same wind direction and speed.
(h) Other than positioning the turbines to be exposed to thesame wind direction and speed, identify one variable that wouldhave been held constant in the investigation.
(i) Identify a reasonable hypothesis for the investigation
(j) Describe how the proposed change from coal to wind coulddecrease the ecological footprint of the community.