A 75.0-g mass is attached to a 1.0-m length of string and whirled around in the air at a rate of 4.0 rev/s when the string breaks. What was the breaking force of the string?

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.