Question

A disc of radius 1 m is rotating about central axis
with angular velocity 2 rad/s. If a point P lying on its
circumference as shown is moving with velocity
4 m/s, then velocity of centre of disc is​

Answer 1

Given:

A disc of radius 1 m is rotating about central axis with angular velocity 2 rad/s.  

A point P lying on its circumference as shown is moving with velocity 4 m/s.

 

To find:

If a point P lying on its circumference as shown is moving with velocity 4 m/s, then velocity of centre of disc is​

Solution:

From given, we have,

A disc of radius 1 m is rotating about the central axis with angular velocity 2 rad/s.  

A point P lying on its circumference as shown is moving with velocity 4 m/s.

we use the formula,

v = rw

where,

r = radius of the disc

w = angular velocity.

Since we need to find the velocity at the centre of the disc, the radius equals to zero.

so, we get,

v =  0 × 2 = 0

Thus the velocity of the centre of the disc is​ zero.