A bird moves from point `(1 m, -2 m, 3 m)` to `(4 m, 2 m, 3 m)`. If the speed of the bird is `10 m//s`, then the velocity vector of the bird in `m//s` is:

Options

A. `5 (hati-2hatj+3hatk)`
B. `5 (4hati+2hatj+3hatk)`
C. `0.6 hat(i)+0.8 hat(j)`
D. `6hat(i)+8hat(j)`

Answer

D

Explanation

`vec(v)=((4-1)hat(i)+(2+2)hat(j)+(3-3)hat(k))/sqrt(3^(2)+4^(2)+0^(2))=(3hati+4hatj)/5`
`vec(v)=|vec(v)|hat(v)=10((3hat(i)+4hatj)/5)=6hat(i)+8hat(j)`