10. When gasoline is used as fuel in an automobile engine several energy transformations take place. Which of the following
statements does NOT agree with the law of conservation of
energy?
a. When gasoline is burned, its energy is destroyed. The
energy from the gasoline can be transformed to produce light. c.
As the energy in the form of gasoline decreases, the energy
increases in another form. d. Once the energy in the gasoline is
released, it can never be destroyed.

Steam is generated in a boiler of a cogeneration plant at 10 mpa and 450°c at a steady rate of 5 kg/s. in normal operation, steam expands in a turbine to a pressure of 0.5 mpa and is then routed to the process heater, where it supplies the process heat. steam leaves the process heater as a saturated liquid and is pumped to the boiler pressure. in this mode, no steam passes through a condenser, which operates at 20 kpa. (a) determine the power produced in the turbine and the rate at which process heat is supplied in this mode. (b) determine the power produced in the turbine and the rate of process heat supplied if only 60 percent of the steam is routed to the process heater and the remainder is expanded to the condenser pressure. (3.32 mw; 9.69 mw; 4.25 mw; 5.82 mw)

Aperson walks first at a constant speed of 4.89 m/s along a straight line from point a to point b and then back along the line from b to a at a constant speed of 2.95 m/s. what is the average speed over the entire trip?

In the cores of extremely hot red giants, nuclear reactions convert helium to