Answer
59,400 J.
Work Step by Step
Solve for the power of the iron.
$$Electric \; power = (current) \times (voltage)$$
$$P = (9 A)(110 V)$$
Solve for P = 990 W.
Find the heat energy generated in 1 minute.
$$E = power \times time = (990 \frac{J}{s})(60 s) = 59,400 J$$