The power P (in W) in an electric circuit is the product of the voltage V and the current I (in A). If the V and I vary with time t (in s) (0 sts 0.2 s), according to V = 0.0760 - 1.20t and I= 2.00 -0.400t, find - dp dt - when t = 0.090 s. It = W/s (Type an integer or decimal rounded to the nearest hundredth as needed.)