The apparatus is initially at rest on a nearly frictionless surface. Then you pull the string with a constant force . At the instant when the center of the disk has moved a distance , an additional length of string has unwound off the disk. (Use any variable or symbol stated above as necessary.) (a) At this instant, what is the speed of the center of the apparatus? Entry field with correct answer Edit Explain your approach. Entry field with incorrect answer now contains modified data I applied the Energy Principle to the system as an extended object. I applied the Energy Principle to the system as a point particle. I applied the Energy Principle to the disk only. I applied the Energy Principle to the small masses only. (b) At this instant, what is the angular speed of the apparatus? Entry field with incorrect answer Edit Explain your approach. Entry field with incorrect answer I applied the Energy Principle to the system as a point particle. I applied the Energy Principle to the small masses only. I applied the Energy Principle to the system as an extended object. I applied the Energy Principle to the disk only.

Lets say that an object of a certain volume has a certin mass. what happens to its mass when you double its volume?

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

In a series circuit the __ is the same at every point