The electric iron is plugged into a 220 volt network. Determine how much heat is released

The electric iron is plugged into a 220 volt network. Determine how much heat is released per minute if the resistance of the heating element of the iron is 73.3 ohms

The amount of heat released during the passage of current is calculated by the formula of the Joule-Lenz law:

Q = I ^ 2 R t;

Let’s remember Ohm’s law I = U / R;

To transform the formula, taking into account the given problem conditions:

Q = (U / R) ^ 2 * t * R = U ^ 2 * t * R / R ^ 2;

Reduce by R, we get:

Q = U ^ 2 * t / R;

For the solution, you need to use a single SI system:

t = 1 min. = 60 s;

Substitute numerical values and calculate:

Q = 220 ^ 2 * 60 / 73.3 = 39618 J;