Question

Is \[\ \left \langle v_x^2+v_y^2+v_z^2 \right \rangle=\left \langle v_x^2\right \rangle+\left \langle v_y^2\right \rangle+\left \langle v_z^2\right \rangle \] correct?

Answer 1

Concerning kinetic theory of gases.

Answer 2

Of course. When working with vectoral components, the vector sum is the sum of the vectors! :D