Acaliper brake is required for the front wheels of a passenger car with a braking capacity of 500 nm for each brake. preliminary design estimates have set the brake geometry as ri = 110 mm1 and θ = 43°. pads with a coefficient of friction of 0.38 have been selected. each pad is actuated by means of a hydraulic cylinder of nominal diameter 25.4 mm. determine: a)- the required actuating force, b)- the average and the maximum contact pressures, c)- the required hydraulic pressure for brake actuation. take the outer radius of the brake to be that of the bugatti chiron. (420.0 mm front brake diameter 400.0mm rear brake diameter)

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?

Afluid flows with a velocity field given by v=(x/t)i.. determine the local and convective accelerations when x=3 and t=1.

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.