During one cycle, a refrigerator removes 500 j from a cold reservoir and discharges 800 j to its hot reservoir. (a) what is its coefficient of performance? (b) how much work per cycle does it require to operate?

Which of the following correctly describes what happens when an atomic bomb explodes? small pieces of fissionable material are joined and form a body with a mass greater than the critical mass, the relative number of neutrons escaping decreases, and a chain reaction and explosion result. large pieces of fissionable matter are brought together quickly and form a body with a mass smaller than the critical mass, the relative number of escaping neutrons increases, and a chain reaction and explosion result.

In a heat engine if 1000 j of heat enters the system and the piston does 500j of work, what is the final internal energy of the system if the inital energy was 2000 j1.write the equation2.list out your known variables 3. plug the numbers into the equations4.solve 5.write your solution statement that includes initial energy and final energy added.

An alarm clock has a current of 4.5 amps and a resistance of 3.2 ohms. what is the voltage in the circuit? a.1.4 volts b.0.71 volts c.14 volts d.46 volts