Consider a long duct constructed with diffuse, gray walls 1 m wide. (a) determine the net radiation transfer from surface a1 per unit length of the duct. (b) determine the temperature of the insulated surface a3. (c) what effect would changing the value of have on your result? after considering your assumptions, comment on whether you expect your results to be exact.

Ajournal bearing has a journal diameter of 3.250 in with a unilateral tolerance of 20.003 in. the bushing bore has a diameter of 3.256 in and a unilateral tolerance of 0.004 in. the bushing is 2.8 in long and supports a 700-lbf load. the journal speed is 900 rev/min. find the minimum oil film thickness and the maximum film pressure for both sae 20 and sae 20w-30 lubricants, for the tightest assembly if the operating film temperature is 160°f. a computer code is appropriate for solving this problem.