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Homework Help: Finding torque to life object at a certain acceleration

  1. Nov 17, 2009 #1
    1. The problem statement, all variables and given/known data

    A motor is connected to a solid cylindrical drum with a diameter of 1.2 m and a mass of 51 kg. A massless rope is attached to the drum and tied at the other end to a 38 \rm kg weight, so the rope will wind onto the drum as it turns.

    What torque must the motor apply if the weight is to be lifted with an acceleration of 1.1 m/s^2
    2. Relevant equations
    i have no idea how to do this problem. Could somebody give a me a step by step walkthrough

    3. The attempt at a solution
    i first did newtons second law for teh mass hanging. i found the force of tension. then i took the force of tension and multiplied it by radius of drum and i got the torque. but i keep getting the wrong answere
    Last edited: Nov 17, 2009
  2. jcsd
  3. Nov 17, 2009 #2
    ignore the rm after the 38
  4. Nov 18, 2009 #3


    User Avatar
    Staff Emeritus
    Science Advisor
    Homework Helper

    Welcome to Physics Forums.

    Sorry, but that is not how we give help here.

    Show us what you got for the tension and torque, and please show how you got it. Then we can provide help.
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