A rod of lightning strikes 400 meters away from a stationary observer. Find the time it takes for the observer to hear a sound in air at STP.
Calculate the time it takes for the light to reach the observer.

Lymphocytes known as blastocysts make antibodies that fight infection. select the best answer from the choices provided t f

When electrons are added to the outermost shell of a carbon atom, it forms--an anion that has a larger anion that has a smaller cation that has a larger cation that has a smaller radius.

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.