An inventor claims to have developed a wonderful new heat engine that operates with a relatively cool (and therefor nonpolluting) flame at 190 degrees celcius, and discharges waste heat to the environment at 20 c. his promotional literature advertises that 45 percent of the fuel energy is converted into useful work. calculate the maximum efficiency that can be expected for such an engine. (if your answer is 45 percent, enter .45) (is he scamming you or not? )

Na food processing facility, a spherical container of inner radius r1 5 40 cm, outer radius r2 5 41 cm, and ther- mal conductivity k 5 1.5 w/m · k is used to store hot water and to keep it at 100°c at all times. to accomplish this, the outer surface of the container is wrapped with a 800-w electric strip heater and then insulated. the temperature of the inner surface of the container is observed to be nearly 120°c at all times. as- suming 10 percent of the heat generated in the heater is lost through the insulation, (a) express the differential equation and the boundary conditions for steady one-dimensional heat conduction through the container, (b) obtain a relation for the variation of temperature in the container material by solving the differential equation, and (c) evaluate the outer surface tempera- ture of the container. also determine how much water at 100°c this tank can supply steadily if the cold water enters at 20°c.

Apulley with mass mp and a radius rp is attached to the ceiling, in a gravity field of 9.81 m/s2 and rotates with no friction about its pivot.

The built in flash in a compact camera is usally capable of giving correct exsposure for distance up to how many meters?