Question

Кипятильник нагревает 1,2 л воды от 12 градусов Цельсия до кипения за 10 минут. Определите силу тока потребляемого кипятильником, если напряжение равно 220В. Удельная теплоёмкость воды 4200 Дж/кг*С. Плотность воды 1000 кг/м³. Выделите общую формулу. Проверьте её размерностью.​

Answer 1

Ответ: 3,36А

Объяснение:

Дано:

V=1,2л=1,2*10⁻³м³

t1=12°C

t2=100°C

U=220В

С=4200Дж/кг°С

ρ=1000кг/м³

t=100мин=600с

-------------------------

I-?

Q=cm(t2-t1)=CVρ(t2-t1)=4200*1000*1,2*10⁻³*(100-12)=443520Дж

Q=UIt

I=Q/Ut=443520/(220*600)=3,36А

Answer 2

To determine the current consumed by the immersion heater, we can use the formula:

Power (P) = Current (I) x Voltage (V)

We are given the following information: - Volume of water (V) = 1.2 liters = 1.2 kg (since the density of water is 1000 kg/m³) - Initial temperature (T₁) = 12°C - Final temperature (T₂) = boiling point (100°C) - Time taken (t) = 10 minutes = 600 seconds - Voltage (V) = 220V - Specific heat capacity of water (c) = 4200 J/kg°C

Step 1: Calculate the heat energy required to raise the temperature of the water

The heat energy required to raise the temperature of the water can be calculated using the formula:

Q = m x c x ΔT

Where: - Q is the heat energy (in joules) - m is the mass of the water (in kg) - c is the specific heat capacity of water (in J/kg°C) - ΔT is the change in temperature (in °C)

In this case, the change in temperature is from 12°C to 100°C.

Step 2: Calculate the power consumed by the immersion heater

The power consumed by the immersion heater can be calculated using the formula:

P = Q / t

Where: - P is the power consumed (in watts) - Q is the heat energy (in joules) - t is the time taken (in seconds)

Now let's calculate the values:

Step 1: Calculate the heat energy required to raise the temperature of the water

The mass of the water (m) is given as 1.2 kg. The change in temperature (ΔT) is 100°C - 12°C = 88°C.

Using the formula Q = m x c x ΔT, we can calculate the heat energy required:

Q = 1.2 kg x 4200 J/kg°C x 88°C

Step 2: Calculate the power consumed by the immersion heater

The time taken (t) is given as 600 seconds.

Using the formula P = Q / t, we can calculate the power consumed:

P = (1.2 kg x 4200 J/kg°C x 88°C) / 600 s

Now let's calculate the values:

Q = 1.2 kg x 4200 J/kg°C x 88°C = 443,520 J

P = (443,520 J) / (600 s) = 739.2 W

Therefore, the power consumed by the immersion heater is 739.2 watts.

The general formula used is P = Q / t, where P is power, Q is heat energy, and t is time.

The dimensions of the formula are as follows: - Power (P) is measured in watts (W) - Heat energy (Q) is measured in joules (J) - Time (t) is measured in seconds (s)

Please note that the above calculations assume that all the electrical energy is converted into heat energy and transferred to the water. In practice, there may be some energy losses due to inefficiencies in the heating element.