Question

A radio wave transmits 38.5 W/m2 of power per unit area. A flat surface of area A is perpendicular to the direction of propagation of the wave. Assuming the surface is a perfect absorber, calculate the radiation pressure on it.

Answer 1

Answer:

$P=2.57\times 10^{-7}\ N/m^2$

Explanation:

Given that,

A radio wave transmits 38.5 W/m² of power per unit area.

A flat surface of area A is perpendicular to the direction of propagation of the wave.

We need to find the radiation pressure on it. It is given by the formula as follows :

$P=\dfrac{2I}{c}$

Where

c is speed of light

Putting all the values, we get :

$P=\dfrac{2\times 38.5}{3\times 10^8}\\\\=2.57\times 10^{-7}\ N/m^2$

So, the radiation pressure is $2.57\times 10^{-7}\ N/m^2$.