Water contained in a closed, rigid tank, initially at 100 lbf/ in.2, 8008F, is cooled to a final state where the pressure is 20 lbf/in.2 Determine the change in specific entropy, in Btu/lb ? 8R, and show the process on sketches of the T– and T–s diagrams.

The higher the astm grain-size number, the coarser the grain is. a)-true b)-false

Air flows over a heated plate àt a velocity of 50m/s. the local skin factor coefficient at a point on a plate is 0.004. estimate the local heat transfer coefficient at this point. the following property data for air are given: density = 0.88kg/m3 , viscosity 2.286 x 10 ^-5 kgm/s , k = 0.035w/mk ,cp = 1.001kj/kgk. use colburn reynolds analogy.

The sum of the normal stresses does not change as the stress state rotates through an angle. a)-trune b)- false