Batteries are a source of what type of energy

During takeoff, the sound intensity level of a jet engine is 170db at a distance of 34 m. what's the sound intensity level at a distance of 1.0 km?

Nacidified solution was electrolyzed using copper electrodes. a constant current of 1.18 a caused the anode to lose 0.584 g after 1.52 ✕ 103 s. given that the charge of an electron is 1.6022 ✕ 10−19 c, calculate avogadro's number. assume that copper is oxidized to cu2+ ions.

An airplane travels from st. louis to portland, oregon in 4.33 hours. if the distance traveled is 2,742 kilometers. what is the airplane's average speed? - the airplane returns to st. louis by the same route. because the prevailing winds push the airplane along, the return trip takes only 3.75 hours. what is the average speed for this trip? - the airplane refuels in st. louis and continues on to boston. it travels at an average speed of 610 km/h. if the trip takes 3.75 hours. what is the flight distance between st. louis and boston?