Into 237.3ml of water initially at 47°c a chunk of copper from an oven at 133.5°c is dropped. the water/copper combination comes to a final temperature of 74.68°c. (a) what is the mass of the copper block? now a mystery substance of mass 172.6 g is taken from the same oven and dropped into the same water+copper, but the temperature only rises to a final temperature of 89.3°c. (b) what is the (mass) specific heat of the mystery substance? (a) g answer part (a) cal/g °c

An internally reversible refrigerator has a modified coefficient of performance accounting for realistic heat transfer processes of where qin is the refrigerator cooling rate, qout is the heat rejection rate, and is the power input. show that copm can be expressed in terms of the reservoir temperatures tc and th, the cold and hot thermal resistances rt, c and rt, h, and qin, as where rtot rt, c rt, h. also, show that the power input may be expressed as 1.39 a household refrigerator operates with cold- and hot-temperature reservoirs of tc 5 c and th 25 c, respectively. when new, the cold and hot side resistances are rc, n 0.05 k/w and rh, n 0.04 k/w, respectively. over time, dust accumulates on the refrigerator’s condenser coil, which is located behind the refrigerator, increasing the hot side resistance to rh, d 0.1 k/w. it is desired to have a refrigerator cooling rate of qin 750 w. using the results of problem 1.38, determine the modified coefficient of performance and the required power input w under (a) clean and (b) dusty coil conditions. internally reversible refrigerator qout qin w high-temperature reservoir low-temperature reservoir th th, i tc, i tc high-temperature side resistance low-temperature side resistance w qin th tc qinrtot tc qinrtot copm tc qinrtot th tc

Gather reliable information to brent make his decision. to gather this information, use newspapers, call insurance companies or look at their web sites, and review consumer magazines and web sites. also, look at the manufacturer web site or for information about gas mileage. list the sources you use and take notes.

A58-kg boy swings a baseball bat, which causes a 0.140-kg baseball to move toward third base with a velocity of 38.0 m/s.