A 65 kg college student stands on an analog bathroom scale inside an elevator car. State the scale
measurement when the elevator. show all work:
a. moves at a constant speed upward.
b. moves at a constant speed downward.
c. accelerates upward at a rate of 3.1 m/s2.
d. accelerates downward at a rate of 3.1 m/s_.

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.