Exercise 40

The voltage \(V\) in a simple electrical circuit is slowly decreasing as the battery wears out. The resistance \(R\) is slowly increasing as the resistor heats up. Use Ohm’s Law, \(V = IR\), to find how the current \(I\) is changing at the moment when \(R = 400\ \Omega\), \(I = 0.08\) A, \(dV/dt = -0.01\) V/s, and \(dR/dt = 0.03\ \Omega\)/s.