Question

The electric field in a traveling em wave in the vacuum has an rms intensity of 6.75 v/m.

Required:
Calculate the amount of energy delivered in average during 3.02x10^7s to 2.00 cm^2 of a wall that it hits perpendicularly?

Answer 1

The amount of energy delivered is 730.84 J

Step-by-step explanation:

Given;

rms intensity of the electric field,
`E_(rms)` = 6.75 v/m

area of the wall, A = 2.0 cm² = 2.0 x 10⁻⁴ m²

The average intensity of the wave is given by;

`I_(avg) = c \epsilon_o E_(rms)^2`

where;

c is the speed of light

ε₀ is permittivity of free space

I = (3 x 10⁸)(8.85 x 10⁻¹²)(6.75)²

I = 0.121 W/m²

Average power delivered, P = I x A

P = 0.121 x 2 x 10⁻⁴

P = 2.42 x 10⁻⁵ W

The amount of energy delivered is calculated as;

E = P x t

E = 2.42 x 10⁻⁵ x 3.02 x 10⁷

E = 730.84 J

Therefore, the amount of energy delivered is 730.84 J