Question

Microwave ovens work by irradiating food with microwaves, which are absorbed by the water molecules in the food and converted to heat. Assuming that microwave ovens emit radiation with a wavelength of 29.7 cm, calculate how many photons are emitted per second in a 600-Watt microwave oven. (1 W = 1 J/s)

Answer 1

8.969×10²⁶ photons

Step-by-step explanation:

From the question,

Using,

E = hc/λ........................... Equation 1

Where E = Energy of the photon, h = Planck's constant, c = speed of light, λ = wave length of the photon.

Given: h = 6.626×10⁻³⁴ J.s, c = 3×10⁸ m/s, λ = 0.297 m

Substitute into equation 1

E = 6.626×10⁻³⁴(3×10⁸)/0.297

E = 6.69×10⁻²⁵ J.

The energy of the photon in one seconds = 6.69×10⁻²⁵ J/s

If the power of the microwave oven = 600 J/s

Then,

Number of photons emitted per seconds = 600/(6.69×10⁻²⁵)

Number of photons emitted per seconds = 8.969×10²⁶ photons