According to the hall-petch relationship, if we decrease the grain size of a metal, we expect the yield strength to a) decrease b) increase c) increase or decrease depending on the alloy d) remain constant. e) none of these

Water at 55c flows across a flat plate whose surface temperature is held constant at 95c. if the temperature gradient at the plate's surface for a given value of x is 18 c/mm, find a) local heat transfer coefficient. b) heat flux

Ahe-xe mixture containing a 0.75 mole fraction of helium is used for cooling electronics in an avionics application. at a temperature of 300 k and atmospheric pressure, calculate the mass fraction of helium and the mass density, molar concentration and molecular weight of the mixture. if the cooling capacity is 10 l, what is the mass of the coolant?

When subject to a steady load (within elastic range) over a long period of time, what is the major difference in material behavoir between steel and plastic?