For any particle moving with some velocity `(vecv)` & acceleration `(veca)`, tangential acceleration & normal acceleration are defined as follows.
Tangential acceleration - The component of acceleration in the direction of velocity.
Normal acceleration - The component of acceleration in the direction perpendicular to velocity.
If at a given instant, velocity & acceleration of a particle are given by .
`vecc=4hati +3hatj`
`veca=10hati+15hatj+20hatk`
Find the normal acceleration of the particles at the given instant :-

Options

A. `(-9hati+12hatj+50hatk)/(5)`
B. `(-9hati-12hatj-50hatk)/(5)`
C. `(-18hati+24hatj+100hatk)/(5)`
D. `(18hati-24hatj-100hatk)/(5)`

Answer

C