A refrigeration cycle operating between two reservoirs receives energy QC from a cold reservoir at TC = 275 K and rejects energy QH to a hot reservoir at TH = 315 K. For each of the following cases, determine whether the cycle operates reversibly, operates irreversibly, or is impossible:
(a) QC = 1000 kJ, Wcycle = 80 kJ.
(b) QC = 1200 kJ. QH = 2000 kJ.
(c) QH = 1575 kJ. Wcycle = 200 kJ.
(d) beta = 6.

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.

Consider a large isothermal enclosure that is maintained at a uniform temperature of 2000 k. calculate the emissive power of the radiation that emerges from a small aperture on the enclosure surface. what is the wavelength ? , below which 10% of the emission is concentrated? what is the wavelength ? 2 above which 10% of the emission is concentrated? determine the wavelength at which maximum spectral emissive power occurs. what is the irradiation incident on a small object placed inside the enclosure?

The thermal expansion or contraction of a given metal is a function of the f a)-density b)-initial temperature c)- temperature difference d)- linear coefficient of thermal expansion e)- final temperature f)- original length