5 A certain wavelength of visible light is incident on a thi

5. A certain wavelength of visible light is incident on a thin layer of ethyl alcohol sitting atop a puddle of water. a) It is found that the smallest non-zero thickness of alcohol that will produce a bright spot on top of the alcohol is 114 nm. What is the wavelength of the light in air? b) How would the problem be different if instead of alcohol atop water, it was alcohol atop glass? Don\'t do any calculations, just describe in words why you would not get the same answer as in part a). A 1.8 eV electron is traveling from a region of zero potential energy to a thin region in which U-0.8 eV followed by a region in which U 1.2 eV. 6.

Solution

a)
f = v/ .. 3.0^8m/s / 589^-9m .. .. .. f = 5.09^14 Hz

b)
(g) = (air) / n .. .. 589^-9m / 1.52 .. .. .. (g) = 3.875^-7m

c)
v(g) = f x (g) .. .. frequency is unchanged

v(g) = 5.09^14 Hz x 3.875^-7m .. .. .. v(g) = 1.97^8 m/s