A beam of white light is incident normally on a plane surface absorbing 70% of the light and reflecting the rest. If the incident beam of light is power P, find the force exerted by it on the surface.

Explanation

To find the force exerted by a beam of white light on a plane surface that absorbs 70% of the light and reflects the rest, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Power of the Incident Beam**:
Let the power of the incident beam of light be \( P \).

2. **Calculate the Energy over Time**:
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