Hot combustion gases of a furnace are flowing througha concrete chimney (k =1.4 w/m · °c) of rectangular cross section. the flow section of the chimney is 20 cm ×40 cm, and the thickness of the wall is 10 cm. the average temperatureof the hot gases in the chimney is ti=280°c, and the averageconvection heat transfer coefficient inside the chimney is hi=75 w/m2· °c. the chimney is losing heat from its outer surfaceto the ambient air at to=15°c by convection with a

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.

Water in a partially filled large tank is to be supplied to the roof top, which is 8 m above the water level in the tank, through a 2.2-cm-internal-diameter pipe by maintaining a constant air pressure of 300 kpa (gage) in the tank. if the head loss in the piping is 2 m of water, determine the discharge rate of the supply of water to the roof top in liters per second.

Which of the following components of a pid controlled accumulates the error over time and responds to system error after the error has been accumulated? a)- proportional b)- derivative c)- integral d)- on/off.