A thin uniform circular disc of mass `M` and radius `R` is rotating in a
Channel: Doubtnut
Date: 2020-08-02

A thin uniform circular disc of mass `M` and radius `R` is rotating in a horizontal plane about an axis passing through its centre and perpendicular to its plane with an angular velocity `omega`. Another disc of the same dimensions but of mass `M//4` is placed gently on the first disc co-axially. show that angular velocity o fthe system is `4 omega//5`.