Answer:
Net electric charge flux is 19.30.
Explanation:
Velocity u =10 z
Charge density ,ρv = - 3r²
r= 0.8 m
The net electric charge given as
[tex]n.e.c.=\oint \rho_v.u.ds[/tex]
u .ds= 10 dA
Now by putting the values
[tex]n.e.c.=\int_{0}^{2\pi}\int_{0}^{0.8}-3r^2.10r.dr.d\theta[/tex]
[tex]n.e.c.=-30\int_{0}^{2\pi}\int_{0}^{0.8}r^3dr.d\theta[/tex]
[tex]n.e.c.=2\pi\left(\dfrac{30r^4}{4}\right)_0^{0.8}\\[/tex]
[tex]n.e.c.=2\pi\left(\dfrac{30\times (0.8)^4}{4}\right)[/tex]
n.e.c=19.30
So the net electric charge flux is 19.30.
