An ideal refrigerator does 130.0 J of work to remove 780.0 J of heat from its cold compartment during each cycle. What is the refrigerator's coefficient of performance

If 21.2 kcals of energy is released by this reaction, how many kj does the reaction release? (1 cal 4.184 j)

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.

Which of the following is the main energy source for the sun? a. fission of hydrogen b. fusion of hydrogen c. fusion of helium d. fission of iron