A flat sheet of crown glass has a thickness of 2.6 cm. It is on top of a flat sheet of crystalline quartz that has a thickness of 3.2 cm. Light strikes the crown glass perpendicularly and travels through it and then through the crystalline quartz. In the time it takes the light to travel through the two sheets, how far would it have traveled in a vacuum

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.