2. naca 2412 airfoil has a zero lift angle of -2.1 degree and a lift curve slope of 2  (if the alpha is expressed in radians). the pitching moment coefficient at the quarter chord is -0.036. compute the lift and pitching moment at quarter chord at a 4 degree angle of attack if the freestream velocity is 50 feet sec, and the chord is 2 feet. assume sea level conditions. (ans: 3.8 lb per foot of span, -0.428 ft. lb per foot of span)

Ahouse has the following electrical appliance usage (1) single 40w lamp used for 4 hours per day (2) single 60w fan used for 12 hours per day (3) single 200w refrigerator that runs 24 hours per day with compressor run 12 hours and off 12 hours find the solar power inverter size in watt with correction factor of 1.25.

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.