An uninsulated steam pipe is used to transport high- temperature steam from one building to another. the pipe is of 0.5-m diameter. has a surface temperature of 150 degree c, and is exposed to ambient air at ? 10 degree c. the air moves in cross flow over the pipe with a velocity of 5 m/s. (a) what is the heat loss per unit length of pipe? (b) consider the effect of insulating the pipe with a rigid urethane foam (k = 0.026 w/m . k). evaluate and plot the heat loss as a function of the thickness of the insulation layer for 0 leq delta leq 50 mm.

Tom is having a problem with his washing machine. he notices that the machine vibrates violently at a frequency of 1500 rpm due to an unknown rotating unbalance. the machine is mounted on 4 springs each having a stiffness of 10 kn/m. tom wishes to add an undamped vibration absorber attached by a spring under the machine the machine working frequency ranges between 800 rpm to 2000 rpm and its total mass while loaded is assumed to be 80 kg a) what should be the mass of the absorber added to the machine so that the natural frequency falls outside the working range? b) after a first trial of an absorber using a mass of 35 kg, the amplitude of the oscillation was found to be 10 cm. what is the value of the rotating unbalance? c) using me-3.5 kg.m, find the optimal absorber (by minimizing its mass). what would be the amplitude of the oscillation of the absorber?