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.
what power setting caused the breaker to trip? a) 600 wb) 900 wc) 1200 wd) 1500 w

Is a  vector quantity  that refers to "the rate at which an object changes its position." imagine a person moving rapidly - one step forward and one step back - always returning to the original starting position. while this might result in a frenzy of activity, it would result in a zero velocity. because the person always returns to the original position, the motion would never result in a change in position. since velocity is defined as the rate at which the position changes, this motion results in zero velocity. if a person in motion wishes to maximize their velocity, then that person must make every effort to maximize the amount that they are displaced from their original position. every step must go into moving that person further from where he or she started. for certain, the person should never change directions and begin to return to the starting position.