In the above example what is the average force if surface is perpectly reflecting?

Explanation

To find the average force exerted on a perfectly reflecting surface by electromagnetic waves, we can follow these steps:

### Step 1: Understand the Momentum of Electromagnetic Waves
The momentum \( p \) of electromagnetic waves can be expressed as:
\[ p = \frac{E}{c} \]
where \( E \) is the energy of the wave and \( c \) is the speed of light.
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