a screw is a type of simple machine. if we look closely at a screw, we see that it is really a wrapped around a central core.

a) wedge
b) lever
c) fulcrum
d) inclined plane

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.