1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Rotational motion 2

  1. Jun 22, 2012 #1
    In the days before compact discs and MP3 players (ancient history!), music was recorded in scratches in the surface of vinyl-coated disks called records. In a typical record player, the record rotated with a period of 3.6 s. Find the centripetal acceleration of a point on the edge of the record. Assume a radius of 8.89 cm.

    So I already converted the radius to meters and got .0889m.

    Now I need to find the velocity in order to plug it into the equation for centripetal acceleration which is Ac=v^2/r...

    How should I go about solving for the velocity so I can get the centripetal acceleration??
     
  2. jcsd
  3. Jun 22, 2012 #2

    SammyS

    User Avatar
    Staff Emeritus
    Science Advisor
    Homework Helper
    Gold Member

    What distance does that point on the edge travel in one second?
     
  4. Jun 22, 2012 #3
    im not sure... So its traveling 2∏ in 3.6s right??
     
  5. Jun 22, 2012 #4

    SammyS

    User Avatar
    Staff Emeritus
    Science Advisor
    Homework Helper
    Gold Member

    Yes.

    Then, how far does the point on the edge travel in 3.6 seconds?
     
  6. Jun 22, 2012 #5
    360 degrees. So then in one second I think it travels 100 degrees??
     
  7. Jun 22, 2012 #6
    So I found that the acceleration is 1.745rad/s^2. Then I plugged it into the equation for average acceleration to find the velocity and got 6.28m/s... is this correct??
     
  8. Jun 22, 2012 #7

    SammyS

    User Avatar
    Staff Emeritus
    Science Advisor
    Homework Helper
    Gold Member

    I don't think so.

    What is the circumference of the circle made by the point on the edge?
     
  9. Jun 22, 2012 #8
    .1778m is the circumfrance
     
  10. Jun 22, 2012 #9
    how does the circumference help me im confused??
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Rotational motion 2
  1. Rotation 2 (Replies: 5)

Loading...