Using lumped capacitance, find the temperature of a cube of aluminum (k =250 w/mk, ρ=2500 c=900 1/kg-k), 0.1 m in length, 30 seconds after it is placed in a barrel of oil (h=2500 w/m2k, k ,k= 0.12 w/mk). the oil is at 25c and the initial temperature of the aluminum cube is 1200c. discuss the accuracy of using lumped capacitance for this problem.

The temperature of air decreases as it is compressed by an adiabatic compressor. a)- true b)- false

Coiled springs ought to be very strong and stiff. si3n4 is a strong, stiff material. would you select this material for a spring? explain.

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.