The sound level at 1.0 m from a certain talking person talking is 60 db. you are surrounded by five such people, all 1.0 m from you and all talking equally loud at the same time. the threshold of hearing is 1.0 × 10-12 w/m2. what sound level are you being exposed to? you can neglect any absorption, reflection, or interference of the sound. the threshold of hearing is 1.0 × 10-12 w/m2.

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.