A 36 ft simply supported beam is loaded with concentrated loads 16 ft inwards from each support. On the left side, the dead load is 8.0 kips and the live load is 18.0 kips. On the other side, the dead load is 4.0 kips and the live load is 9.0 kips. Self-weight of the beam can be ignored. Lateral supports are provided at the supports and the load points. Determine the least-weight W-shape to carry the load. Use A992 steel, Cb = 1.0 and Table 3.10 of the 15th edition of the Manual. check if a W21×62 will be sufficient considering the correct Cb. Do not use Table 3.10 and work the problem with calculations.

Air is to be cooled in the evaporator section of a refrigerator by passing it over a bank of 0.8-cm-outer-diameter and 0.4-m-long tubes inside which the refrigerant is evaporating at -20°c. air approaches the tube bank in the normal direction at 0°c and 1 atm with a mean velocity of 4 m/s. the tubes are arranged in-line with longitudinal and transverse pitches of sl- st 1.5 cm. there are 30 rows in the flow direction with 15 tubes in each row. determine (a) the refrigeration capacity of this system and (b) pressure drop across the tube bank. evaluate the air properties at an assumed mean temperature of -5°c and 1 atm. is this a good assumption?

Thermal stresses are developed in a metal when its a) initial temperature is changed b) final temperature is changed c) density is changed d) thermal deformation is prevented e) expansion is prevented f) contraction is prevented

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]