Which of the following is an example of a physical variable of water quality *

Physical properties of water quality include temperature and turbidity. While chemical characteristics involve parameters such as pH and dissolved oxygen. These parameters are relevant not only to surface water studies of the ocean, lakes and rivers, but to groundwater and industrial processes as well.

I hope this is the answer if not I apologize :P

One of the physical variables that affect the properties of water is temperature

Explanation:

I assume that by physical properties you mean external factors that affect the properties of the water correct? well depending on the temperature of the air that the water is exposed to the war can shift from either a liquid to a solid if it if the air is cold or it can change from a liquid to a gas when the air is hot. I'll explain how this works when the temperature of the air is hot the water will under go an exo thermic reaction (A reaction that causes things to emit heat and become hot) and because water boils at a certain point as the water gets hotter and hotter it will evaporate into mist. If the air around the water is cold then it produces an endothermic reaction which will cause the ice to get colder and colder as time goes on until it transitions from being a liquid to a solid in the form of ice. Hope this helps:)

its temperature is increasing. this causes molecular vibrations to increase.