A pipeline, used for the transport of crude oil, is buried in the earth such that its centerline is a distance of 0.5 m below the surface. The pipe has an outer diameter of 0.5 m and is insulated with a layer of cellular glass 200 mm thick. What is the heat loss per unit length of pipe when heated oil at 120°C flows through the pipe and the surface of the earth is at a temperature of 0°C?

The temperature of air decreases as it is compressed by an adiabatic compressor. a)- true b)- false

Aloaded platform of total mass 500 kg is supported by a dashpot and by a set of springs of effective stiffness 72 kn/m. it is observed that when the platform is depressed through a distance x = 12.5 cm below its equilibrium position and then released without any initial velocity; it reaches its equilibrium position in the shortest possible time without overshoot. find the position and velocity of the loaded platform 0.10 sec. after its release. if a further load of 400 kg is added to the platform, find, i) the frequency of damped vibrations, and i) the amplitude of vibration after 2 complete oscillations, given that the initial amplitude is 15 cm.

Acompressor receives the shaft work to decrease the pressure of the fluid. a)- true b)- false