If there is a moth sitting at point `C` of rolling sphere, where velocity of the centre of mass `=v`, calculate the velocity of the moth as seen by an oberver sitting at point `D` at this instant

Options

A. `sqrt(2)v` at `45^(@)` to the horizontal
B. `2v` horizontal
C. `v` at `45^(@)` to horizontal
D. `2v` going down

Explanation

`omega=(v)/(R )`
`v_(c.g)=vhati+Romegahatj=vhati+vhatj`
`v_(D.g)=vhati+Romega(-hatj)=vhati-vhatj`
`v_(C.D)=v_(c.g)-v_(d.g)=vhati+vhatj-vhati+vhatj=2vhatj`