Aboys sits on a merry-go-round so that he is alwasy locatedat

r =8 ft from the center of rotation. the merry-go-round

isoriginally at rest, and then due to rotation the boy's speed

isincreased at 2 ft/s2. determine the time needed for

hisacceleration to become 4 ft/s2.

Air inially occupying a volume of 1 m2 at 100 kpa, 27 c undergoes three internally reversible processes in series. process 1-2 compression to 500 kpa during which pv constant process 2-3 adiabatic expanslon to 100 kpa process 3-1: constant-pressure expansion to 100 kpa (a) calculate the change of entropy for each of the three processes. (b) calculate the heat and work involved in each process. (c) is this cycle a power cycle or refrigeration cycle?