State, for each of the following physical quantities, if it is a scalar or a vector : volume, mass, speed, acceleration, density, number of moles, velocity, angular frequency, displacement, angular velocity.

Find the unit vector of a vector whose co-ordinates are $(8,\, 6)$.

If $\overrightarrow A $ is $(3,\, 4)$ unit, then show that the value of its unit vector is $1$.

Pick out the two scalar quantities in the following list :

force, angular momentum, work, current, linear momentum, electric field, average velocity, magnetic moment, relative velocity.