What is the available energy content, in joules, of a battery that operates a 2.00-W electric clock for 18 months

The energy equivalent of the rest mass of an electron is

Two kilograms of air within a piston–cylinder assembly executes a carnot power cycle with maximum and minimum temperatures of 800 k and 300 k, respectively. the heat transfer to the air during the isothermal expansion is 60 kj. at the end of the isothermal expansion the volume is 0.4 m3. assume the ideal gas model for the air. determine the thermal efficiency, the volume at the beginning of the isothermal expansion, in m3, and the work during the adiabatic expansion, in kj.

The three classes of rocks are sedimentary, metamorphic, and igneous. how are rocks classified into one of these three groups?