An electric heater uses 600 kJ of electrical energy in 5 minutes. Calculate its power rating.

Explanation

To find the power rating of the electric heater, we can follow these steps:

### Step 1: Understand the relationship between energy, power, and time
Power is defined as the rate at which work is done or energy is transferred. The formula for power (P) is given by:
\[ P = \frac{W}{t} \]
where \( W \) is the work done (or energy used) and \( t \) is the time taken.

### Step 2: Identify the given values
From the problem, we know:
- The energy used by the heater, \( W = 600 \) kJ (kilojoules)
- The time taken, \( t = 5 \) minutes

### Step 3: Convert the time from minutes to seconds
Since power is usually expressed in watts (joules per second), we need to convert the time from minutes to seconds:
\[ t = 5 \text{ minutes} \times 60 \text{ seconds/minute} = 300 \text{ seconds} \]

### Step 4: Convert energy from kilojoules to joules
Next, we convert the energy from kilojoules to joules:
\[ W = 600 \text{ kJ} \times 1000 \text{ J/kJ} = 600,000 \text{ J} \]

### Step 5: Calculate the power using the formula
Now we can use the power formula:
\[ P = \frac{W}{t} = \frac{600,000 \text{ J}}{300 \text{ s}} \]

### Step 6: Perform the calculation
Calculating the power:
\[ P = \frac{600,000}{300} = 2000 \text{ W} \]

### Step 7: Convert watts to kilowatts
Since 1 kW = 1000 W, we convert the power to kilowatts:
\[ P = \frac{2000 \text{ W}}{1000} = 2 \text{ kW} \]

### Final Answer
The power rating of the electric heater is **2 kW**.

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