Problem 3.98

# Problem 3.98 - Problem *3.98 [Difficulty: 3] Given: Data on...

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Problem *3.98 [Difficulty: 3] F buoyancy W load y W hot air Given: Data on hot air balloon Find: Maximum mass of balloon for neutral buoyancy; mass for initial acceleration of 2.5 ft/s 2 . Assumptions: Air is treated as static and incompressible, and an ideal gas Solution: Basic equation F B ρ atm g V = and Σ F y Ma y = Hence Σ F y 0 = F B W hotair W load = ρ atm g V ρ hotair g V Mg = for neutral buoyancy MV ρ atm ρ hotair () = Vp atm R 1 T atm 1 T hotair = M 320000 ft 3 14.7 × lbf in 2 12 in ft 2 × lbm R 53.33 ft lbf × 1 48 460 + R 1 160 460 + R × = M 4517 lbm = Initial acceleration Σ F y F B W hotair W load = ρ atm ρ hotair g V M new g = M accel a = M new 2 ρ hotair V + a = Solving for M new ρ atm ρ hotair g V M new g M new 2 ρ hotair V + a = M new V ρ atm ρ hotair g 2 ρ hotair
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## This note was uploaded on 10/19/2011 for the course EGN 3353C taught by Professor Lear during the Fall '07 term at University of Florida.

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