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

Answer:

$intensity = 12.98 W/m^2$

$Energy = 3.93 J$

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

$intensity = \frac{1}{2}\epsilon_0 E^2 c$

$intensity = \frac{1}{2}(8.85 \times 10^{-12})(98.9)^2(3\times 10^8)$

$intensity = 12.98 W/m^2$

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

$Energy = Area \times time \times intensity$

$Energy = 0.0259(11.7)(12.98)$

$Energy = 3.93 J$