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Mech Engineering Question

  1. Mar 11, 2012 #1
    1. The problem statement, all variables and given/known data

    was wondering if anybody here does mech engineering and if so can they point me in the right direction of this question please.


    Figure 1 below shows a drum of mass of 50kg and radius 350mm. The drum can be assumed to be a uniform solid cylinder. A rope of negligible mass is wrapped around the drum and is attached to a load of 15kg which is held 2.4m above the ground initially. Determine:
    • the linear acceleration of the 15kg load when the brake preventing the drum from rotating is released and
    • the velocity with which the 15kg load will impact the ground with.

    (Assume the acceleration due to gravity is 9.8 m/s2.)

    drum-1.png


    2. Relevant equations

    q = qo + wo t + (1/2)a t2
    w2 = wo
    2 + 2 a q

    to start, i am not looking the answer and i just want someone to please show me how to get the linear acceleration

    thanks
    1. The problem statement, all variables and given/known data



    2. Relevant equations



    3. The attempt at a solution
     
  2. jcsd
  3. Mar 11, 2012 #2

    tiny-tim

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    welcome to pf!

    hi brooker2009uk! welcome to pf! :smile:

    (btw, this is a fairly standard dynamics problem also, so you'll get answered sooner if you post future questions like this in the physics homework forum :wink:)

    you'll need F = ma for the load, and τ = Iα for the drum …

    (and also the rolling constraint, a = rα)

    call the tension "T" …

    what do you get? :smile:
     
  4. Mar 11, 2012 #3
    thank you, that is getting the torque but i need an equation to get the linear acceleration of the load when the brake is released
     
  5. Mar 11, 2012 #4

    tiny-tim

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    yes, that's F = ma !

    get on with it! :smile:
     
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