Thrust to weight ratio and Weight Problems
1) If a 22450lb (total gross weight) airplane develops 8160lbf thrust from each of its two engines and has a wing area of 312ft2 and wing-span of 53.5ft. And a empty weight of 11770lbf. Determine the thrust to weight ratio and the wing loading of this aircraft?
2) Consider an ordinary, helium-filled party balloon with a volume of 2.2ft3 . The lifting force on the balloon due to the outside air is the net resultant of the pressure distribution exerted on the exterior surface of the balloon. Using this
fact, Archimedes Principle can be derived, namely that the upward force on the balloon is equal to the weight of the air displaced by the balloon. Assuming the balloon is at sea level, standard atmospheric conditions, calculate the maximum
weight that can be lifted by the balloon.
Note: the molecular weight of air is 28.8 and that helium is 4. What if the helium is replaced by hydrogen, molecular weight of 1?