The quantity of charge q (in coulombs) that has passed through a surface of area 2.05 cm2 varies with time according to the equation q = 6t3 + 7t + 6, where t is in seconds.
(a) What is the instantaneous current through the surface at t = 0.950 s?
_________ A
(b) What is the value of the current density?
______kA/m2