Question

A uniform wheel of radius R is set into rotation about

its axis at an angular speed or. This rotating wheel is

now placed on a rough horizontal surface with its axis

horizontal. Because of friction at the contact, the wheel

accelerates forward and its rotation decelerates till the

wheel starts pure rolling on the surface. Find the linear

speed of the wheel after it starts pure rolling.

Answer 1

A uniform wheel of radius R is set into rotation about its axis (case-I) at an angular speed ω.
This rotating wheel is now placed on a rough horizontal. Because of its friction at contact, the wheel accelerates forward and its rotation decelerates. As the rotation decelerates the frictional force will act backward.
If we consider the net moment at A then it is zero.
Therefore the net angular momentum before pure rolling & after pure rolling *** constant
Before rolling the wheel was only rotating around its axis.