An industrial laser is used to burn a hole through a piece of metal. The average intensity of the light is W/m². What is the rms value of the electric field in the electromagnetic wave emitted by the laser?

I think your question should be:

An industrial laser is used to burn a hole through a piece of metal. The average intensity of the light is

What is the rms value of (a) the electric field and

(b) the magnetic field in the electromagnetic wave emitted by the laser

a)

b)

Explanation:

To find the RMS value of the electric field, let's use the formula:

Where

;

;

Therefore

b) to find the magnetic field in the electromagnetic wave emitted by the laser we use:

;

;

Complete Question:

An industrial laser is used to burn a hole through a piece of metal. The average intensity of the light is 1.38 * 10⁹ W/m². What is the rms value of the electric field in the electromagnetic wave emitted by the laser?

E = 7.21 * 10⁶ N/C

Explanation:

S = 1.38 * 10⁹ W/m²(1)

The formula for the average intensity of light can be given by:

S = c∈₀E²

The speed of light, c = 3 * 10⁸ m/s²

Permittivity of air, ∈₀ = 8.85 * 10⁻¹²m-3 kg⁻¹s⁴ A²

Substituting these parameters into equation (1)

1.38 * 10⁹ = 3 * 10⁸ * 8.85 * 10⁻¹² * E²

E² = (1.38 * 10⁹)/(3 * 10⁸ * 8.85 * 10⁻¹²)

E² = 0.052 * 10¹⁷

E = 7.21 * 10⁶ N/C