Two objects are placed in a tank of water (density of 1.0 g/mL). Object A sinks, while object B floats. Which of the following statements must be true?
I. Object A must be less dense than object B.
II. Object A must be more dense than object B.
III. Object B must be less dense than 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.