Suppose that you have left a 200-ml cup of coffee sitting until it has cooled to 30∘c , which you find totally unacceptable. your microwave oven draws 1100 w of electrical power when it is running. if it takes 45 s for this microwave oven to raise the temperature of the coffee to 60∘c , what is the efficiency of heating with this oven?

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 astronaut on the moon throws a baseball upward. the astronaut is 6 ft, 6 in. tall, and the initial velocity of the ball is 3030 ft per sec. the height s of the ball in feet is given by the equation s equals negative 2.7 t squared plus 30 t plus 6.5s=−2.7t2+30t+6.5, where t is the number of seconds after the ball was thrown. complete parts a and b.

You can estimate the degree to which a bond between two atoms is ionic or covalent by calculating the