Air flows with a mass rate of 0.1 kg/s through an aluminum circular pipe of inner diameter d, 0.15 m and outer diameter do-0.20 m at inlet temperature of 100°c. after traveling l-10 m, the air cools down to 75°c. outside the pipe, heat transfer from the pipe to the surroundings takes place by convection and radiation a to=tsur =20°c and a combined convection and condtuction heat transfer coefficient of 5 w/m2.k a)- calculate the heat loss in watts from the duct over the whole pipe. b)- draw the equivalent thermal circuit and calculate the value of all thermal resistances. c)-determine the heat flux and the duct surface temperature at x=l .

If you were designing a bumper for a car, would you prefer it to exhibit elastic or plastic deformation? why? consider the functions of a bumper in both a minor "fender-bender" and a major collision.

During a steady flow process, the change of energy with respect to time is zero. a)- true b)- false

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?