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Homework Help: Problem nº1 from Strenght of Materials by J.P. Den Hartog (1949)

  1. May 15, 2010 #1
    1. The problem statement, all variables and given/known data

    A propeller shaft in the largest and most powerful ships transmits about 50,000 hp. Assume that the propeller transforms this power into a forward push on the ship with an efficiency of 70 per cent and that the ship's speed then is 30 knots (1 knot is 6,080 ft/hr).

    The shaft is 300 ft long from the propeller to the thrust bearing in the engine room, where the thrust is transmitted to the ship's hull structure. The diameter of the (solid, circular) shaft is 24 in. Calculate the elastic contraction of the shaft at full power.
    (Answer:0.985 in).

    2. Relevant equations

    They are attached in my attempt solution.

    3. The attempt at a solution View attachment My fail solution.doc
    Last edited: May 16, 2010
  2. jcsd
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