A glass plate 2.25 mm thick, with an index of refraction of 1.80, is placed between a point source of light with wavelength 620 nm (in vacuum) and a screen. The distance from source to screen is 1.50 cm. How many wavelengths are there between the source and the screen?

There are 2.71x10⁴ wavelengths between the source and the screen.

Explanation:

The number of wavelengths (N) can be calculated as follows:

Where:

: is the distance in glass = 2.25 mm

: is the distance in air = 1.50 cm - 0.225 cm = 1.275 cm

: is the wavelength in glass

: is the wavelength in air = 620 nm

To find the wavelength in glass we need to use the following equation:

Where:

: is the refraction index of glass = 1.80

: is the refraction index of air = 1

Hence, the number of wavelengths is:

Therefore, there are 2.71x10⁴ wavelengths between the source and the screen.

I hope it helps you!

what is the question?

this would be about 43%