Question

Водонагреватель при напряжении 220 В нагревает воду с 12 °С до кипения за 8 мин. Чему равна масса воды, если сила тока 5 А? КПД водонагревателя 42 %.

Answer 1

Ответ:

см фото

Объяснение:

Answer 2

Calculation of the Mass of Water

To calculate the mass of water heated by the water heater, we can use the formula:

Q = m * c * ΔT

Where: - Q is the heat energy transferred to the water - m is the mass of the water - c is the specific heat capacity of water - ΔT is the change in temperature of the water

In this case, the initial temperature of the water is 12 °C, and it is heated to the boiling point, which is 100 °C. Therefore, the change in temperature (ΔT) is 100 °C - 12 °C = 88 °C.

The specific heat capacity of water is approximately 4.18 J/g°C.

To find the heat energy transferred to the water (Q), we can use the formula:

Q = P * t

Where: - P is the power of the water heater - t is the time taken to heat the water

In this case, the power of the water heater is given as 220 V * 5 A = 1100 W.

The time taken to heat the water is given as 8 minutes.

Now, let's calculate the mass of water using the above formulas:

Q = m * c * ΔT