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Angular acceleration x radius= Acceleration of center of mass ?

  1. Nov 24, 2013 #1
    For a rotating body,
    (angular acceleration x radius)= Acceleration of center of mass ?

    But a rotating body can have angular acc. even if it is not translating. what is wrong?
  2. jcsd
  3. Nov 24, 2013 #2
    no no no........... angular acc. x radius = the linear acc. of a point on the body , ie the tangential velociti of that point with respect to the centre of mass
  4. Nov 24, 2013 #3
    the point is moving around the body with a speed= R x α
    where α= angular acceleration
  5. Nov 24, 2013 #4
    Hi Aakash...

    The correct relationship for a point on a rotating body is

    atan = αr where ,

    atan=tangential acceleration of the point with respect to center of the axis

    α = angular acceleration of the rotating body

    r= distance between the point and the center of the axis

    The relationship acm = αr is a constraint which is sometimes obtained in cases when a body is rotating as well as translating.

    For eg. a sphere rolling without slipping on floor .
  6. Nov 24, 2013 #5
    i have told the same........:cool:
  7. Nov 24, 2013 #6
    Your language is sloppy and inaccurate .

    The item in red should be acceleration.

    Again ,instead of center of mass,you should have used center of rotation.

    That doesn't make any sense . Neither the point is moving around the body ,nor is speed equal to R x α
  8. Nov 24, 2013 #7
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