# physics

posted by
**priya** on
.

The quantity of charge q (in coulombs) that has passed through a surface of area 2.08 cm2 varies with time according to the equation q = 4t3 + 5t + 6, where t is in seconds.

(a) What is the instantaneous current through the surface at t = 1.08 s?

(b) What is the value of the current density?