Ahydrologist from a government agency tests several samples of water for safety. as part of his examinations, he determines the concentration of lead that is present in each sample. which method of expressing concentration should the hydrologist use to describe the concentration of lead in the water?

A1500 w electric heater is plugged into the outlet of a 120 v circuit that has a 20 a circuit breaker. you plug an electric hair dryer into the same outlet. the hair dryer has power settings of 600 w, 900 w , 1200 w, and 1500 w. you start with the hair dryer on the 600 w setting and increase the power setting until the circuit breaker trips. under what setting does the circuit breaker trip.