Asmall block with a mass of 0.0600 kg is attached to a cord passing through a hole in a frictionless, horizontal surface (figure 1) . the block is originally revolving at a distance of 0.47 m from the hole with a speed of 0.63 m/s . the cord is then pulled from below, shortening the radius of the circle in which the block revolves to 9.0×10? 2 m . at this new distance, the speed of the block is 3.29 m/s .

a small block with a mass of 0.0600 kg& n

part a.) what is the tension in the cord in the original situation when the block has speed v0 = 0.63 m/s ? (t=? )

part b.) what is the tension in the cord in the final situation when the block has speed v1 = 3.29 m/s ? (t=? )

part c.) how much work was done by the person who pulled on the cord? (w=? )

i really need to understand this : o

Which feature of a heating curve indicates a change ofn state

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

Atomic nuclei of almost all elements consist of