Position of a particle in a rectangular-co-ordinate system is $(3, 2, 5)$. Then its position vector will be
$3\hat i + 5\hat j + 2\hat k$
$3\hat i + 2\hat j + 5\hat k$
$5\hat i + 3\hat j + 2\hat k$
None of these
Angular momentum is
Surface area is
Explain null vector. Explain the physical significance of null vector.
Find the unit vector of a vector whose co-ordinates are $(8,\, 6)$.
A vector is represented by $3\,\hat i + \hat j + 2\,\hat k$. Its length in $XY$ plane is