A student sets up an experiment to investigate particle motion and heat transfer. He attaches a paperclip to an iron rod with wax. He suspends the iron rod above a spirit lamp and lights the spirit lamp to heat the rod. The setup is shown below. image A. The particles in the rod move towards the heat as the rod is heated by the spirit lamp. The movement of these particles causes the wax to become heated and melt, letting the paperclip fall to the table. B. The particles in the rod move away from the heat as the rod is heated by the spirit lamp. The movement of these particles causes the wax to become heated and melt, letting the paperclip fall to the table. C. The particles in the rod nearest to the spirit lamp begin to move faster when heated. These particles collide into nearby particles, slowly transferring heat energy along the rod to reach the wax. This causes the wax to melt, letting the paperclip fall to the table. D. The particles in the rod nearest to the spirit lamp begin to move slower when heated. These particles form a rigid grid with nearby particles, slowly transferring heat energy along the rod to reach the wax. This causes the wax to melt, letting the paperclip fall to the table.

The primary benefit of taking into account a child's interests while selecting exercise activities is that the child will a. play more willing with others b. succeed at their favorite activity c. allow parents to relax afterwards d. gain motivation to exercise select the best answer from the choices provided.

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

A0.580-kg rock is tied to the end of a string and is swung in a circle with a radius of 0.500 meters. the velocity of the rock is 4.50 m/s. what is the centripetal force acting on the rock? 15.5 n 5.22 n 69.8 n 23.5 n