The model shows the star Wolf 359, the sun, and Star X. It takes 7.8 years for light produced on Wolf 359 to reach the sun. If Star X is 50 times as far from the sun as Wolf 359 is, how far is Star X from the sun, to the nearest light-year?

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?

How are series and parallel circuits simililar? both have multiple paths for electrons to travel. both require resistors in their circuits. both require a switch to complete the circuit. both have at least one path for electrons to travel.

Explain the comparisons between nature and packingtown that appears on pages 81 and 82 answer