Gujarati
6.System of Particles and Rotational Motion
normal

A flat surface of a thin uniform disk $A$ of radius $R$ is glued to a horizontal table. Another thin uniform disk $B$ of mass $M$ and with the same radius $R$ rolls without slipping on the circumference of $A$, as shown in the figure. A flat surface of $B$ also lies on the plane of the table. The center of mass of $B$ has fixed angular speed $\omega$ about the vertical axis passing through the center of $A$. The angular momentum of $B$ is $n M \omega R^2$ with respect to the center of $A$. Which of the following is the value of $n$ ?

A$2$
B$5$
C$\frac{7}{2}$
D$\frac{9}{2}$
(IIT-2022)

Solution

$v =\omega(2 R )$
$v =\omega_0 R \text { : no slipping }$
$\therefore \omega_0=2 \omega$
$\overrightarrow{ L }= m \overrightarrow{ r } \times \overrightarrow{ v }_{ c }+ I _c \omega_0$
$= M 2 Rv +\frac{1}{2} MR ^2 \omega_0$
$=4 MR ^2 \omega+\frac{1}{2} MR ^2(2 \omega)=5 MR ^2 \omega$
$\therefore n =5$
Standard 11
Physics

Similar Questions

Start a Free Trial Now

Confusing about what to choose? Our team will schedule a demo shortly.