Question

A traveling electromagnetic wave in a vacuum has an electric field amplitude of 98.9 V/m . Calculate the intensity ???? of this wave. Then, determine the amount of energy ???? that flows through area of 0.0259 m2 over an interval of 11.7 s , assuming that the area is perpendicular to the direction of wave propagation.

Answer 1

`intensity = 12.98 W/m^2`

`Energy = 3.93 J`

Step-by-step explanation:

As we know that the magnitude of electric field intensity is given as

`E = 98.9 V/m`

now we know that intensity of the wave is given as the product of energy density and speed of the wave

`intensity = (1)/(2)\epsilon_0 E^2 c`

`intensity = (1)/(2)(8.85 * 10^(-12))(98.9)^2(3* 10^8)`

`intensity = 12.98 W/m^2`

so intensity is the energy flow per unit area per unit of time

so the energy that flows through the area of 0.0259 m^2 in 11.7 s is given as

`Energy = Area * time * intensity`

`Energy = 0.0259(11.7)(12.98)`

`Energy = 3.93 J`