Along 35-cm-diameter cylindrical shaft made of stain-less steel 304 (k = 14.9 w/m·°c, ρ = 7900 kg/m3, cp = 477 j/kg·°c, and α = 3.95x10-6 m2/s) comes out of an oven at a uniform temperature of 400°c. the shaft is then allowed to cool slowly in a chamber at 150°c with an average convection heat transfer coefficient of h = 60 w/m2 · °c. determine the temperature at the center of the shaft 20 min after the start of the cooling process. also, determine the heat transfer per unit length of the shaft during this time period.

Aforce of 34.5 newtons is applied to an object at an angle of 45 º with the horizontal. what is the force acting on the object in the horizontal direction?

As part of an industrial process, air as an ideal gas at 10 bar, 400k expands at steady state through a valve to a pressure of 4 bar. the mass flow rate of air is 0.5 kg/s. the air then passes through a heat exchanger where it is cooled to a temperature of 295k with negligible change in pressure. the valve can be modeled as a throttling process, and kinetic and potential energy effects can be neglected. (a) for a control volume enclosing the valve and heat exchanger and enough of the local surroundings that the heat transfer occurs at the ambient temperature of 295 k, determine the rate of entropy production, in kw/k. (b) if the expansion valve were replaced by an adiabatic turbine operating isentropically, what would be the entropy production? compare the results of parts (a) and (b) and discuss.

One object has a mass of 1 kg and another object has a mass of 3 kg. if the speeds are the same, which of the following is true about their kinetic energy?