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Homework Help: Angular speed and linear speed

  1. Oct 10, 2011 #1
    1. The problem statement, all variables and given/known data

    a ball moves at 5000 rpm (revolutions per minute). Their radius is 4 cm.

    (i)Determine the angular speed in radians per second.

    (ii) Find the period of rotation

    (iii) Find the linear speed of a point on the outer ball

    (iv) Find the linear acceleration of a point on the outer edge of the ball.

    2. Relevant equations

    angular speed = 2∏ / T

    3. The attempt at a solution

    (i)

    r = 4cm = 0.04m
    circumference = 2∏r = 0.08∏

    1 rev = 2∏°
    5000 rev/min = 5000 X 2∏° / min
    10,000∏° / min
    10,000∏° / min = 10,000∏° per 60 secs

    10,000∏° / 60 = 166.67∏°/sec

    angular speed = 166.67∏°/sec

    is this correct for part (i)
     
    Last edited: Oct 10, 2011
  2. jcsd
  3. Oct 10, 2011 #2
  4. Oct 10, 2011 #3

    lightgrav

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    Homework Helper

    1 rev = 2∏ radians = 360° ; be careful with your units.
    You might as well say that omega = 523.6 rad/sec.
     
  5. Nov 17, 2011 #4
    Find the period of rotation

    T = 2 ∏ / omega = 2∏/523.6 = 0.012 seconds
     
  6. Nov 18, 2011 #5
    is this correct?
     
  7. Nov 19, 2011 #6
    why isnt anyone responding?
     
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