Question

do #5

you will need to look at #4 to understand how to do #5

4. The open-circuit voltage of a battery is 12 volts and it's internal (i.e., source) resistance is one ohm Using a load resistor as a heating element to extract maximal power from the battery to heat up a container of 1 cubic meter of water (to be used as a thermal reservoir for a steam engine). (a) How long (i.e., how many seconds) does it take to bring that water from 32 degrees Celsius to 90 degrees Celsius? (b) With the above as a hot reservoir and room temperature air as a cold reservoir (at 32 degrees Celsius) how much work (per cycle) can you extract from a steam engine operated in a Carnot cycle when the maximum volume of the steam is 10 cubic meters and the minimum volume of the steam is 2 cubic meters ? [The steam has a gamma-7/2. 5. (a) repeat 4(a) if the 12 volt battery is replaced by a solar-thermal collector of collection area2 (square meters) and the water absorbs none of the energy between 400nm and 1125nm (but absorbs all of the rest of it). 5. (b) repeat 4(b) if the Carnot cycle is replaced by a Stirling cycle.

Answer 1

tto 6 diventhat 32 cto O C et time taken bethen 2 p. 402 1 sec bJ 2Hiciency of Casnot engine -> h- 30 363

hence maximum heat extoad ed ho S1 E.xo