Question

The magnitude of the Poynting vector of a planar electromagnetic wave has an average value of 0.939 W/m2. The wave is incident upon a rectangular area, 1.5 m by 2.0 m, at right angles. How much total electromagnetic energy falls on the area during 1.0 minute

Answer 1

The total energy is
`T = 169.02 \ J`

Step-by-step explanation:

From the question we are told that

The Poynting vector (energy flux ) is
`k = 0.939 \ W/m^2`

The length of the rectangle is
`l = 1.5 \ m`

The width of the rectangle is
`w = 2.0 \ m`

The time taken is
`t = 1 \ minute = 60 \ s`

The total electromagnetic energy falls on the area is mathematically represented as

`T = k * A * t`

Where A is the area of the rectangle which is mathematically represented as

`A= l * w`

substituting values

`A= 2 * 1.5`

`A= 3 \ m^2`

substituting values

`T = 0.939 * 3 * 60`

`T = 169.02 \ J`