One BTU (British thermal unit ) represents the amount of heat required to raise the temperature of one pound of water to `1^@ F` (from `62^@ F` to `63^@F`) BTU = …………………. Cal.

Explanation

To solve the question of how many calories are in one British thermal unit (BTU), we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Definition of BTU**:
- One BTU is defined as the amount of heat required to raise the temperature of one pound of water by 1°F, specifically from 62°F to 63°F.

2. **Know the Conversion Factor**:
- It is important to know the conversion between BTU and calories. The conversion factor is:
\[ 1 \text{ BTU} = 252 \text{ calories} \]

3. **Write the Conversion**:
- Based on the conversion factor, we can express BTU in terms of calories:
\[ \text{BTU} = 252 \text{ cal} \]

4. **Final Answer**:
- Therefore, we conclude that:
\[ \text{BTU} = 252 \text{ cal} \]

### Final Result:
\[ \text{BTU} = 252 \text{ calories} \]

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