Question

The position vector of a particle is `r = a sin omega t hati +a cos omega t hatj`
The velocity of the particle is
A. parallel to positive vector
B. perpendicular to position vector
C. directed towards the origin
D. directed away from the origin

Answer 1

Correct Answer - B
`vecr= (a cos omegat) hati + ( a sin omegat)hatj`
`(dvecr)/(dt) = vecv =- a omegasin omegat hati + aomega cos omegathatj`
`because" " vecr. vecv= 0`
`So, vecr" ""is" bot "to "vecv`