Explanation:
Groundwater is the freshwater present below the earth's surface. It originates from the rain, ice, melting snow.
Some anthropogenic sources of groundwater pollution are
Groundwater pollution has more problems than surface water pollution because groundwater is mostly hidden and it is very difficult to view, manage and monitor.
Groundwater holds its contamination and pollutants that cause pollution whereas surface water rinses their contamination and pollutants.
The independent variable is the amount of water consumed by the football players.
The dependent variable is the football players' endurance, measured by how many times they can run up and down the bleachers before catching their breaths.
The coach's hypothesis was that the more water consumed, the more endurance the players will have.
There is not a control group present in this experiment, but it would be the set of players who did not drink a bottle of water before practice.
The experimental group is the set of players who did drink a bottle of water before practice.
The constants in the experiment are the operational definitions of endurance (how he measures their endurance), the amount of water each player drinks throughout the week, and the players used in the experiment.
The lack of a set control group poses a threat to the accuracy of the experiment's results.