A 100 W light bulb is placed at the centre of a spherical chamber of radius 20cm. Assume that 60% of the energy supplied to the bulb is converted into light and that the surface of the chamber is perfectly absorbing. Find the pressure exerted by the light on the surface of the chamber.

Explanation

To find the pressure exerted by the light on the surface of the chamber, we can follow these steps:

### Step 1: Calculate the power converted into light
Given that the light bulb has a power of 100 W and 60% of this power is converted into light, we can calculate the power of light emitted.

\[ \text{Power of light} = \text{Total power} \times \text{Percentage converted to light} \]
...