Consider the velocity and temperature profiles for air- flow in a tube with diameter of 8 cm can be expressed as 11(r) = 0.21(1-(r/r)21 tr) = 250 + 200( r/r)3 with units in m/s and k, respectively. if the convection heat transfer coefficient is 100 w/m2.k, determine the mass flow rate and surface heat flux using the given velocity and tem- perature profiles. evaluate the air properties at 20°c and 1 atm. properties the density of 1 atm air at 20°c is p-1.204 kg/m

If you were designing a bumper for a car, would you prefer it to exhibit elastic or plastic deformation? why? consider the functions of a bumper in both a minor "fender-bender" and a major collision.

Apure substance is a)-mixture of various chemical elements or compounds b)-substance that has a fixed chemical composition throughout c)-mixture that is homogeneous (such as air) d)-all the answers

Acarnot refrigerator operates in a room in which the temperature is 21°c and of power when operating. if the food compartment of the refrigerator is consumes 3 kw to be maintained at 2°c, determine (a) the coefficient of performance of the cycle and (b) the rate of heat removal from the food compartment. refrigerator cycle that has a higher coefficient of performance than that of the discussed (e) is it possible to develop a carn ot refrigerator, operating between the same temperature limits? explain