One kilowatt hour is equal to

Options

A. `36xx10^(5)J`
B. `36xx10^(3)J`
C. `10^(3)J`
D. `10^(5)J`

Answer

To convert one kilowatt hour (kWh) into joules (J), we can follow these steps:

### Step 1: Understand the units
1 kilowatt (kW) is equal to 1000 watts (W). Therefore, 1 kWh can be expressed as:
\[ 1 \text{ kWh} = 1000 \text{ W} \times 1 \text{ hour} \]

### Step 2: Convert hours to seconds
Since the standard unit of time in the International System of Units (SI) is seconds, we need to convert hours into seconds.
1 hour is equal to 60 minutes, and 1 minute is equal to 60 seconds:
\[ 1 \text{ hour} = 60 \text{ minutes} \times 60 \text{ seconds/minute} = 3600 \text{ seconds} \]

### Step 3: Calculate energy in joules
Now substituting the time in seconds into our equation:
\[ 1 \text{ kWh} = 1000 \text{ W} \times 3600 \text{ seconds} \]
Calculating this gives:
\[ 1 \text{ kWh} = 1000 \times 3600 \text{ W s} = 3,600,000 \text{ J} \]
or
\[ 1 \text{ kWh} = 3.6 \times 10^6 \text{ J} \]

### Step 4: Conclusion
Thus, we conclude that:
\[ 1 \text{ kWh} = 3.6 \times 10^6 \text{ J} \]

### Final Answer
One kilowatt hour is equal to \( 3.6 \times 10^6 \) joules.

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