Consider a thin‐walled, metallic tube of length l = 1 m and inside diameter di = 3 mm. water enters the tube at ˙ m = 0.015 kg / s m˙=0.015 kg/s and tm, i = 97°c. a. what is the outlet temperature of the water if the tube surface temperature is maintained at 27°c? ( b. if a 0.5‐mm‐thick layer of insulation of k = 0.05 w/m-k is applied to the tube and its outer surface is maintained at 27°c, what is the outlet temperature of the water? c. if the outer surface of the insulation is no longer maintained at 27°c but is allowed to exchange heat by free convection with ambient air at 27°c, what is the outlet temperature of the water? the free convection heat transfer coefficient is 5 w/m2 -k.

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?