Afriend in your class tells you that she never uses hints when doing her mastering homework. she says that she finds the hints , but when the hint asks another question it increases the chance that her score on the problem will go down. she feels like it isn't worth the risk. you reassure her that there is nothing to fear about opening a hint that asks a question. which of the following are good reasons for your friend not to worry?

An air standard cycle with variable specific heats is executed in a closed system and is composed of the following four processes. 1-2 isentropic compression 100 kpa and 22°c to 600 kpa 2-3 v=constant heat addition to 1500 k 3-4 isentropic expansion to 100 kpa 4-1 p=constant heat rejection to initial state (a) show the cycle on p-v and t-s s (b) calculate the net work output per unit mass (409 kj/kg) (c) determine the thermal efficiency (47.9%)