How much heat must be spent to heat a 3 kg cast iron frying pan from 20 to 270 degrees.

The formula for calculating the amount of heat for heating a cast iron pan:

Q = C * m * (tк – tн); C is the specific heat capacity (for cast iron C = 540 J / (kg * K)), m is the weight of the cast iron frying pan (m = 3 kg), tк is the final temperature of the frying pan (tк = 270 ºС), tн is the initial temperature of the frying pan (tн = 20 ºС).

Let’s calculate the heat:

Q = С * m * (tк – tн) = 540 * 3 * (270 – 20) = 540 * 3 * 250 = 405000 J = 405 kJ.

Answer: To heat a cast-iron frying pan, you need to spend 405 kJ of heat.