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 carries 10 W of power , find the force exerted by it on the surface .

Explanation

To solve the problem step by step, we will follow these calculations:

### Step 1: Determine the power absorbed and reflected
Given that the incident power of the beam is 10 W and 70% of the light is absorbed, we can calculate the absorbed power.

\[ \text{Power absorbed} = \text{Incident power} \times \text{Percentage absorbed} = 10 \, \text{W} \times 0.70 = 7 \, \text{W} \]
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