Find the angle between two plane mirrors if the number of images formed are 4

Bone-strengthening physical activity done increases bone-mineral content and bone density in youth.

Acoal-fired plant generates 600 mw of electric power. the plant uses 4.8 x 10^6 kg of coal each day, and the heat of combustion of coal is 3.3x 10^7 j/kg. the steam that drives the turbines is at a temperature of 300° c, and the exhaust water is at 37° c. (a) what is the overall efficiency of the plant for generating electric power? (b) how much thermal energy is exhausted each day? (c) what is the change in entropy of the universe for this heat engine? (d) using the same heat reservoirs, what is the maximum possible (carnot) efficiency for a heat engine?

Acombination reaction is when two or more combine to form one product. a decomposition reaction is when a substance breaks down into two or more simpler substances in a chemical reaction.