dI/dt depends on v?

[Kolahal Bhattacharya]

As we know,a single moving charge creats a current J=rho*v=qv^2*delta(r-vt) supposing that the charge moves along x axis.However,it is not a steady current.Making I=J.dS,how can we calculate the dI/dt?I suppose,it will depend on v in such a manner that if v increases,dI/dt will increase...Any help?(Note it's not a homework question)

[ZapperZ]

But it is a HOMEWORK/SCHOOLWORK-TYPE question, so it still belongs there.

Zz.