392_Dynamics 11ed Manual

392_Dynamics 11ed Manual - which the fuel must be burned so...

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Engineering Mechanics - Dynamics Chapter 15 Problem 15-127 If the chain is lowered at a constant speed v , determine the normal reaction exerted on the floor as a function of time. The chain has a weight W and a total length l . Given: W 5 lb ft = l 20 ft = v 4 ft s = Solution: At time t , the weight of the chain on the floor is WM g v t () = t v d d 0 = M t Mv t () = t M t d d Mv = Σ F s M t v d d v Dt t M t d d + = RM g v t () 0 vMv () + = RM g v tv 2 + () = R W g gvt v 2 + () = * Problem 15-128 The rocket has mass
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Unformatted text preview: which the fuel must be burned so that its thrust gives the rocket a speed v in time t starting from rest. The fuel is expelled from the rocket at relative speed v r . Neglect the effects of air resistance and assume that g is constant. Given: M 65000 lb = v r 3000 ft s = v 200 ft s = g 32.2 ft s 2 = t 10 s = 390...
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This note was uploaded on 08/16/2011 for the course EGN 3321 taught by Professor Christianfeldt during the Spring '08 term at University of Central Florida.

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