A 4-in-wide polyamide F-2 flat belt is used to connect a 3-in-diameter pulley to drive a larger pulley with an angular velocity ratio of 0.3. The center-to-center distance is 10 ft. The angular speed of the small pulley is 1500 rev/min as it delivers 3 hp. The service is such that a service factor Ks of 1.3 is appropriate. a) Find Fc, Fi, (F1)a, and F2, assuming operation at the maximum tension limit. b) Find Ha, L, and the safety factor nfs. c) Find the dip

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?