Question
A disc is rotating with angular velocity ω about an axis passing through the centre and perpendicular to the plane of disc. A body of mass m is placed at the distance r from the centre of the disc. If the coefficient of friction between disc and body is μ then at what angular velocity will the body just slip?
Solution
Let a body of mass m be placed on the disc at a distance r from the centre.
Coefficient of friction between disc and body= μ
Therefore,
Limiting friction between body and disc = μmg.
Let
be the angular velocity of the disc.
The body will be just at the point of slipping when centrifugal force is just equal to the force of friction.
Hence,
, is the angular velocity when the body will just slip.
Coefficient of friction between disc and body= μ
Therefore,
Limiting friction between body and disc = μmg.
Let
be the angular velocity of the disc. The body will be just at the point of slipping when centrifugal force is just equal to the force of friction.
Hence,
, is the angular velocity when the body will just slip.
