A 12 volt battery is hooked up to a variable resistor $R$, so that a current $I$ flows through the resistor
given by the formula $IR = 12$, where $I$ is measured in amperes, and $R$ is in ohms. If the
resistance, $R$, is increased at a constant 2000 ohms/min, then how fast does the current, $I$, change
at the instant when the resistance is 10,000 ohms? Show all your work, and as always, give units.