Question

No friction on horizontal surface

the two plates are the same (drawing). Symbols of lines and

angular velocity as the side, dimensions R and r (R> r), va

Touch is elastic. Determine the rear disc speed

touch.

Answer 1

We have given radius of two plates as r and R

According to Impulse momentum theorem,

Impulse = Change in momentum

P =mv, where v is the linear velocity

Using relation between angular and linear velocity  $v=\omega\times r$ ,with the angular velocity

$v=\omega r$ , where $\omega$ is the angular velocity P=$m \omega R$

P=$m \omega R$  as r=R

r=R in above problem therefore $w=\dfrac{P}{mR}$

$w=\dfrac{P}{mR}$  is the angular velocity of plate of radius R