In Exercise 17.7 we saw that the photocurrent of a salamander rod can be approximated by the function R(t) = R0t n

e

−kt

, where t is in units of s, and R is in units of pA. For simplicity, just set R0 = k = 1 and let n = 3.

You definitely want to compute these integrals on a computer, not by hand.

a. What is ∫

R(t) dt?

b. How much charge comes in during the first second?

c. How much charge comes in during the first 10 seconds?

d. How much charge comes in during the first 20 seconds?

e. How long does it take for the channel to shut off so it has effectively zero current?