A microwave oven produces electromagnetic radiation

[jlmac2001]

I need help with the following questions.

1.A microwave oven produces electromagnetic radiation at lambda = 12.3cm and produces a power of 764W. Calculate the number of microwave photons produced by the microwave oven each second.




2.Compton used photons of wavelength 71.3 pm. (a) What is the energy of these photons? (b) What is the wavelength of the photon scattered at theta = 130o? (c) What is the energy of the photon scattered at this angle?

 

[quantumdude]

Originally posted by jlmac2001
I need help with the following questions.

OK, but Forum policy requires you to show how you started and where you got stuck. Since you haven't done that yet, I will answer your question in general terms.

1.A microwave oven produces electromagnetic radiation at lambda = 12.3cm and produces a power of 764W. Calculate the number of microwave photons produced by the microwave oven each second.

From the power of the oven, you can determine the EM energy produced per unit time. From the wavelength of the radiation, you can determine the energy of each photon. From that, you can determine the number of photons produced per second.

2.Compton used photons of wavelength 71.3 pm. (a) What is the energy of these photons? (b) What is the wavelength of the photon scattered at theta = 130o? (c) What is the energy of the photon scattered at this angle?

Part (a) should be a piece of cake. Part (b) uses the Compton shift formula, which should be in your book. Part (c) is done just like part (a).

 

[M98Ranger]

1. The number of microwave photons produced by the microwave oven each second can be calculated using the formula N = P/E, where N is the number of photons, P is the power and E is the energy of each photon. First, we need to convert the wavelength from centimeters to meters, which gives us lambda = 0.123m. Using the formula E = hc/lambda, where h is Planck's constant and c is the speed of light, we can calculate the energy of each photon to be 1.62 x 10^-24 J. Plugging this value into the formula N = P/E, we get N = 4.71 x 10^27 photons per second.

2. (a) Using the formula E = hc/lambda, where h is Planck's constant and c is the speed of light, we can calculate the energy of the photon to be 2.78 x 10^-15 J.

(b) To calculate the wavelength of the photon scattered at theta = 130o, we can use the formula lambda' = (h/mc)(1-cos(theta)), where h is Planck's constant, m is the mass of the electron and c is the speed of light. Plugging in the given values, we get lambda' = 1.23 x 10^-10 m.

(c) Using the formula E = hc/lambda, where h is Planck's constant and c is the speed of light, we can calculate the energy of the photon scattered at this angle to be 1.61 x 10^-15 J.