Question

Помогите!!!!ЗАДАЧА! Нагреватель мощностью 600 Ват за 5 минут нагрел 1 кг води на 30 градусов.Найти ККД

Answer 1

Η = $\frac{A poleznaja}{A zatrachennaja}$ * 100 % 

А полезная = c * m * Δt 

c - удельная теплоёмкость ( для воды 4200 Дж / кг * С )
m - масса ( 1 кг )
Δt - разности температур ( 30 С - 0 С = 30 С )

А п = 4200 * 1 * 30 = 126000 Дж

А затраченная = P * t 

P - мощность ( 600 Вт )
t - время ( 5 мин = 300 с )

А з = 600 * 300 = 180000 Дж

η = $\frac{126000}{180000}$ = 0,7 * 100 = 70 % 

Answer 2

Calculation of Efficiency (ККД) of a Heater

To find the efficiency (ККД) of a heater, we need to know the power of the heater, the time it takes to heat the water, and the change in temperature of the water.

Given: - Power of the heater: 600 Watts - Time taken to heat the water: 5 minutes - Change in temperature of the water: 30 degrees Celsius

Efficiency (ККД) is defined as the ratio of the useful output energy to the input energy. In this case, the useful output energy is the heat transferred to the water, and the input energy is the electrical energy consumed by the heater.

To calculate the efficiency, we can use the formula:

Efficiency (ККД) = (Useful Output Energy / Input Energy) * 100

The useful output energy can be calculated using the formula:

Useful Output Energy = Mass of Water * Specific Heat Capacity of Water * Change in Temperature

Let's calculate the efficiency step by step:

Step 1: Calculate the useful output energy: - Mass of water: 1 kg - Specific heat capacity of water: 4200 J/kg°C (source - Change in temperature: 30°C

Useful Output Energy = 1 kg * 4200 J/kg°C * 30°C = 126,000 J

Step 2: Calculate the input energy: - Power of the heater: 600 Watts - Time taken to heat the water: 5 minutes = 300 seconds

Input Energy = Power * Time = 600 W * 300 s = 180,000 J

Step 3: Calculate the efficiency: Efficiency (ККД) = (Useful Output Energy / Input Energy) * 100 = (126,000 J / 180,000 J) * 100 = 70%

Therefore, the efficiency (ККД) of the heater is 70%.

Please note that the specific heat capacity of water used in this calculation is an approximate value. The actual specific heat capacity of water may vary slightly depending on the temperature range.