Consider a flat plate with the surf-ace heat flux specified as ,, l2O W/m2 when 0 { x { 15 cm, 4,, : ll0 W/m2 when x ) 15 cm. Air at atmospheric pressure and 20"C flows over this plate at 3 m/s. Estimate the variation of wall temperature with the distance x fiom the leading edge in the laminar boundary layer region, and evaluate the wall temperature numerically at 30 cm.

Afluid flows with a velocity field given by v=(x/t)i.. determine the local and convective accelerations when x=3 and t=1.

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

Athin walled concentric tube exchanger is used to cool engine oil from 160°c to 60°c with water that is available at 25°c acting as a coolant. the oil and water flow rates are each at 2 kg/s, and the diameter of the inner tube is 0.5 m and the corresponding value of the overall heat transfer coefficient is 250 w/m2. oc. how long must the heat exchanger be to accomplish the desired cooling? cpwater=4.187 kj/kg-candcpengine el=2.035 kj/kg·°c, oil . 120]