Question

Кипятильник нагревает 10 литров вода, с начальной температурой 40С, за 20 минут. Найти мощность кипятильника. Теплоотдачей в окружающую среду пренебречь. Удельная теплоемкость воды 4200 Дж/кг*С.

Answer 1

$cm(t_2-t_1)=Nt$
$N = \frac{c\rho V(t_2-t_1)}{t}$

Answer 2

Calculation of Power

To find the power of the kettle, we can use the formula:

Power = Energy / Time

The energy can be calculated using the formula:

Energy = Mass * Specific Heat Capacity * Change in Temperature

Given: - Volume of water (V) = 10 liters = 10,000 grams - Initial temperature (t1) = 40°C - Final temperature (t2) = boiling point of water = 100°C - Time (t) = 20 minutes = 20 * 60 seconds = 1,200 seconds - Specific heat capacity of water (c) = 4200 J/kg°C

First, let's calculate the change in temperature:

Change in Temperature (ΔT) = t2 - t1 = 100°C - 40°C = 60°C

Next, let's calculate the energy:

Energy = Mass * Specific Heat Capacity * Change in Temperature

Substituting the values:

Energy = 10,000 g * 4200 J/kg°C * 60°C = 25,200,000 J

Finally, let's calculate the power:

Power = Energy / Time

Substituting the values:

Power = 25,200,000 J / 1,200 s = 21,000 J/s = 21,000 Watts

Therefore, the power of the kettle is 21,000 Watts.