Coefficients of friction always involve how many materials? a. 0 b. 1 c. 2 d. 3

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

The maximum shear stress and maximum flexural stress occur at the same location along a beam subjected to a non-uniform bending load. a)-trune b)- false

Consider airflow over a flat plate of length l = 1.5 m under conditions for which transition occurs at le = 0.9 m based on the critical reynolds number, re,e = 5 x 10. evaluating the thermophysical properties of air at 400 k, determine the air velocity. (hint: use the tables to find the properties of air)