It is proposed to use liquefied petroleum gas (lpg) in spark-ignition engines. a typical sample of the fuel on a volume basis consists of: 80% propane c3h8, 10% butane c4h10, 10% propene c3h6 the higher heating values of the fuels are 50.38 mj/kg for propane, 49.56 mj/kg for butane, and 48.95 mj/kg for propene. a) show and balance the overall combustion reaction for stoichiometric combustion of 1 mole of lpg with atmospheric air, and determine the stoichiometric f/a and a/f ratios. b) what are the higher and lower heating values per unit mass of lpg?

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.

Coiled springs ought to be very strong and stiff. si3n4 is a strong, stiff material. would you select this material for a spring? explain.

Aquick transition of the operating speed of a shaft from its critical speed will whirl amplitude. (a) increase (b) limit (c) not affect (d) zero