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Homework Help: Help with a torque-rotational-inertia-force question please!

  1. Nov 3, 2005 #1
    A cylindrical fishing reel has a moment of inertia of I=6.22×10-4 kg·m2 and a radius of 4.44 cm. A friction clutch in the reel exerts a restraining torque of 1.34 N·m if a fish pulls on the line. The fisherman gets a bite, and the reel begins to spin with an angular acceleration of 66.5 rad/s2. What is the force of the fish on the line?

    I would like to know if the proper acceleration to use here to calculate force would be the tangential acceleration. Also, when I use T = Fxr... does the value of F get subtracted from the force the fish is pulling with? I also can't figure out how to use the inertia in this because if I solve for mass using I = MR^2 .... thats the mass of the reel which makes no sense in using to calculate force. Anyway any help would be greatly appreciated! Thanks in advance!
  2. jcsd
  3. Nov 4, 2005 #2


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    Homework Helper

    You just work with angular acceleration.

    The eqn to use here is T= Iα

    You are given the values of I and α, so what is the torque providing this (angular) accln ?

    You are given the resisting torque of the reel, so what must be the additional torque supplied by the fish ?

    And finally, what must be the force giving this torque ?
  4. Nov 4, 2005 #3
    Thank you so much for your help. I made it a lot more complicated than that method. I worked it out and got the correct answer. Thanks again!
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