Asix-lane divided highway (three lanes in each direction) is on rolling terrain with two access points per mile and has 10- ft lanes, with a 5-ft shoulder on the right side and a 3-ft shoulder on the left side. the peakhour factor is 0.9, and the directional peak-hour volume is 3500 vehicles per hour. there are 7% single-unit trucks and 3% tractortrailer trucks in the traffic stream. no speed studies are available, but the posted speed limit is 55 mi/h. determine the level of service.

Acommercial grade cubical freezer, 4 m on a side, has a composite wall consisting of an exterior sheet of 5.0-mm thick plain carbon steel (kst= 60.5 w/m k), an intermediate layer of 100-mm thick polyurethane insulation (kins 0.02 w/m k), and an inner sheet of 5.0- mm thick aluminium alloy (kal polyurethane insulation and both metallic sheets are each characterized by a thermal contact resistance of r 2.5 x 104 m2 k/w. (a) what is the steady-state cooling load that must be maintained by the refrigerator under conditions for which the outer and inner surface temperatures are 25°c and -5°c, respectively? (b) for power saving purpose, which wall material should be increased/reduced in. thickness in order to reduce 50% of the cooling load found in part (a)? redesign the thickness of the proposed material. 177 w/m-k). adhesive interfaces between the q=575.93 w