Question

What is the approximate number of wavelengths of light that can travel in 1 direction within a retroreflecting bead that has a diameter of 5 × 10–5 m? (Note: The speed of light = 3 × 108 m/s, and its frequency is approximately 1015Hz.)

Answer 1

`N = 166.67`

Step-by-step explanation:

As we know that the wavelength of light is given by

`\lambda = (c)/(f)`

now we know that

`c = 3* 10^8 m/s`

`f = 10^(15) Hz`

now from above equation we know

`\lambda = (3 * 10^8)/(10^(15))`

`\lambda = 3* 10^(-7) m`

now the diameter of the bead is given as

`D = 5 * 10^(-5) m`

Now total number of wavelengths that travel in the bead is given as

`N = (D)/(\lambda)`

`N = (5 * 10^(-5))/(3 * 10^(-7))`

`N = 166.67`