In a four bar mechanism, l, is a fixed link; l2 is driver crank; l3 is coupler and l4 is follower crank. l=27 cm, l3 =5 cm and l4=10 mm. find the length of the link l1 if the linkage can be classified as a double rocker mechanism:

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?

State the stress optic law in two dimension and obtain an expression for the same.

What is the fuid acceleration in vector form for the following velocity field? note i, j, and k are unit vectors. show all of your work.