sole and show work to b a is correct A small heliumneon lase

sole and show work to b. a is correct

A small helium-neon laser produces a light beam with an average power of 3.1 mW and a diameter of 3.0 mm. (Assume the wavelength of light is 632.8 nm.)
(a) How many photons per second are emitted by the laser?
___9.875*10^15___photons/s

(b) What is the amplitude of the electric field of the light wave? Compare this result with the electric field at a distance of 1 m from an incandescent light bulb that emits 100 W of visible light.

laser ________ V/m
light bulb   _______ V/m

Solution

n/t = p * lambda / h c

= (3.1 * 10^-3 * 632.8 * 10^-9) / (6.625 * 10^-34 * 3 * 10⁸)

= 9.87 * 10¹⁵ photons/s

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I = P / A = 3.1 * 10^-3 / pi * (1.5 * 10-3)² = 438.56 W/m²

E = sqrt [2 I / c e] = sqrt [2 * 438.56 / 3 * 10⁸ * 8.85 * 10^-12]

= 574.77 V/m

Lightbulb calculations = 100 / 4pi 1² = 7.96 W/m²

E = sqrt [2 I / c e] = sqrt [2 * 7.96 / 3 * 10⁸ * 8.85 * 10^-12]

= 77.43 V/m