Question

A body of mass `m` and radius `r` is released from rest along a smooth inclined plane of angle of inclination `theta`. The angular momentum of the body about the instantanoues point contact after a time `t` from the instant of release of equal is :
A. `mgrt cos theta`
B. `mgrt sin theta`
C. `(3//2)mgrt sin theta`
D. None of these

Answer 1

Since the surface is frictionless, the body does not rotate about its centre of mass. Only it slides with certain velocity `v` parallel to the surface
`:. omega=0` and `v=(g sintheta)t`
`rArr ` The angular momentum after `a` time`t` is given as
`L=mvr rArr L=mvr`
`rArr L=mg rt sintheta`