it is estimated that per minute, each `cm^2` of earth recives about 2 calories of heat energy from the sun. This constant is called solar constant S. Express solar constant in SI units.

Explanation

To express the solar constant in SI units, we need to convert the given value from CGS units to SI units. The solar constant is given as 2 calories per minute per cm².

### Step-by-Step Solution:

1. **Identify the given values**:
- Heat energy received = 2 calories
- Time = 1 minute
- Area = 1 cm²
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