The thickness of the plastic in plastic bags is about 0.001 mm. How many wavelengths of red light is this?

Question

I am not sure how i would set this up to figure it out. Would I use the frequency of red-light and caluclate it with 3x10^8 m/s for visible light? But how would I factor in the 0.001 mm, I would compare...? Thanks...

so then woudl I need to convert from red light to mm? I really do not understand how to do this stuff.. If anyone could help explain i'd be so thankful :D

Answer 1

Red light should be about 600nm. Plastic is 0.001mm thick, that seems too small to me?

Answer 2

You need to look up the electromagnetic spectrum. Typically it is from red at 700 nm to violet at 400 nm.

0.001 mm = 1,000 nm

if red has a wavelength of 700 nm, then the plastic bag has only about 1.4-1.5 wavelength for red light

Answer 3

You don't need the speed of light. This is entirely a comparison of length.

Red light has a wavelength of 650 nm.

1 mm = 1000000 nm

So do a conversion.

Answer 4

Red light wavelength is apporx. = 700 nm = 0.0007 mm

0.001 mm / 0.0007 mm = approx. 1.43

Answer 5

Wavelength of red light is 650nm or 650x10^-9m