A wing component on an aircraft is fabricated from an aluminum alloy that has a plane strain fracture toughness of 28 . It has been determined that fracture results at a stress of 120 when the maximum internal crack length is 9.2 . For this same component and alloy, compute the stress level at which fracture will occur for a critical internal crack length of 6.6 .(Enter your answer to three significant figures.)

During a steady flow process, the change of energy with respect to time is zero. a)- true b)- false

Determine whether or not it is possible to compress air adiabatically from k to 140 kpa and 400 k. what is the entropy change during this process?

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?