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

Answer

D

Explanation

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