Question

A disc of mass `m` and radius `R` moves in the `x-y` plane as shown in Fig. The angular momentum of the disc about the origin `O` at the instant shown is

A. `-5/2 mR^(2) omegak`
B. `7/3 mR^(2)omegak`
C. `-9/2 mR^(2)omegak`
D. `5/2 mR^(2) omegak`

Answer 1

Correct Answer - A
`L=I_(cm)omega+m(vec(r)xxvec(v)_(cm))`
`1/2MR^(2)omegahatk+m(4Rhati+3Rhatj)xx(omegaRhati)`
`=-5/2MR^(2)omegahatk`