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Homework Help: Angular acceleration of a drill

  1. Nov 2, 2009 #1
    1. The problem statement, all variables and given/known data
    A dentist's drill starts from rest. After 2.90 s of constant angular acceleration it turns at a rate of 2.20 x 10^4 rev/min.
    (a) Find the drill's angular acceleration (in rad/sec^2).
    (b) Determine the angle (in radians) through which the drill rotates during this period.

    2. Relevant equations



    3. The attempt at a solution
    okay so for (a) I thought that I should convert the rev/ min to rad/sec first and got 2303.8 rad/sec and then I used: change in angular velocity/ change in time and got 886.09 but when I input this answer, webassign (thats how we submit homework) says I'm wrong.... I don't know what else to try
     
  2. jcsd
  3. Nov 2, 2009 #2

    hage567

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    Homework Helper

    Are you using 2.9 s for your time? Check your division.
     
  4. Nov 2, 2009 #3
    Ahh Geez... thanks I was going crazy
     
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