Question

Electromagnetic radiation of intensity 0.6 Wn^-2 is falling on a blank surface. The radiation pressure on the surface is: 

• A. 2x10^-9 Nm^-2
• B. 3x10^-9 Nm^-2
• C. 4x10^-9 Nm^-2
• D. 6x10^-9 Nm^-2

Answer 1

The Correct Option is A

To solve the problem, we need to calculate the radiation pressure exerted by electromagnetic radiation of a given intensity on a black surface.

1. Understanding Radiation Pressure:
For a perfectly absorbing (black) surface, the radiation pressure $P$ is related to the intensity $I$ of the electromagnetic radiation by the formula:
$P = \frac{I}{c}$
Where:
- $I$ is the intensity of the radiation,
- $c$ is the speed of light in vacuum, $c = 3 \times 10^8 \, \text{m/s}$

2. Given Values:
- $I = 0.6 \, \text{W/m}^2$
- $c = 3 \times 10^8 \, \text{m/s}$

3. Substituting into the Formula:
$P = \frac{0.6}{3 \times 10^8}$
$P = 2 \times 10^{-9} \, \text{N/m}^2$

Final Answer:
The radiation pressure on the surface is $2 \times 10^{-9} \, \text{Nm}^{-2}$.