Question

Consider the following waves representing electromagnetic radiation: An illustration shows two waves representing electromagnetic radiation. Wave a is a red wave with a wavelength of 1.6 times ten to the power of negative three meters. Wave b is a green wave where the frequency is higher than in wave a. Which wave has the longer wavelength? Calculate the wavelength. Which wave has the higher frequency and larger photon energy? Calculate these values. Which wave has the greater velocity? What type of electromagnetic radiation does each wave represent?

Answer 1

Answer:

a) red wave hs a longer wavelength than the green wave

b)f = 1.875 10¹¹ Hz ,  f_green = 5.45 10¹⁴Hz

c)   E = 1.24 10⁻²² J , E_green = 3.6 10⁻¹⁹ J

d) The red wave is in the infrared range, heat waves

The green wave is in the visible wavelength

Explanation:

a) The green wave are on the left in the electromagnetic spectrum so the red wave has a longer wavelength than the green wave

The green wavelength is in the range of 550 10⁻⁹ m

The speed of the wave is

            c = λ f

            f = c /λ

b) The frequency of the red wave is

            f = 3 10⁸ / 1.6 10⁻³

            f = 1.875 10¹¹ Hz

For the green wave

           f_green = 3 10⁸/550 10⁻⁹

           f_green = 5.45 10¹⁴Hz

c) The photon energy is given by the Planck equation

             E = h f

             E = 6.63 10⁻³⁴ 1.875 10¹¹

             E = 1.24 10⁻²² J

For the green wave

              E_green = 6.63 10⁻³⁴ 5.45 10¹⁴

              E_green = 3.6 10⁻¹⁹ J

d) The speed of electromagnetic waves is constant and has a value of 3 108 m / s

e)  

The red wave is in the infrared range, heat waves

The green wave is in the visible wavelength