A particle of fluid is flowing in a wind tunnel where the velocity components are given by vx = U 1 + a 2 r 2 − 2a 2x 2 r 4 , vy = − 2U a2xy r 4 , vz = 0, where r 2 = x 2+y 2 and where U and a are given constants. A fixed electrical conductor on the z-axis creates the electrostatic potential field P given by P = A cos(qt) ln(x 2 + y 2 ), where A and q are constants. If the moving particle is at (a, a, 0) and t = t1, express the rate of change of P as seen by the particle at t1 in terms of the given quantities.

Amass of m 1.5 kg of steam is contained in a closed rigid container. initially the pressure and temperature of the steam are: p 1.5 mpa and t 240°c (superheated state), respectively. then the temperature drops to t2= 100°c as the result of heat transfer to the surroundings. determine: a) quality of the steam at the end of the process, b) heat transfer with the surroundings. for: p1.5 mpa and t 240°c: enthalpy of superheated vapour is 2900 kj/kg, specific volume of superheated vapour is 0. 1483 m/kg, while for t 100°c: enthalpy of saturated liquid water is 419kj/kg, specific volume of saturated liquid water is 0.001043m/kg, enthalpy of saturated vapour is 2676 kj/kg, specific volume of saturated vapour is 1.672 m/kg and pressure is 0.1 mpa.

During a steady flow process, the change of energy with respect to time is zero. a)- true b)- false

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.