The human eye responds to a light stimulus (generates a sensation of "light") upon receiving light energy of 10eV (and more). If we take 6000 angstroms as the average wavelength, how many photons must the eye receive to register a light sensation?

Answer 1

How much energy do you have in 6000 A?
E = hc/wavelength (w must be in meters) and E is then energy/photon.

Then convert 10 eV to joules, and
Joules = E/photon x # photons and solve for # photons.

Answer 2

PLS dR bob cna explain beter bcs i cant understand......thanks in advance

Answer 3

Hello Bob,

I calculated it without converting to Joules by taking the planck constant with the eV as unit, but i get around 4.84 photons, which seems to be wrong. Any ideas?

Answer 4

Pete, the dimensional analysis is wrong. You should just convert the eV to joules.

Answer 5

even after converting to joules we get the same answer 4.835 which is wrong.

Answer 6

Guys, the mathematics is correct. Look at what is being asked. It's simple.

Answer 7

Right... I was thinking the same along the lines of light is "quantized". Thanks!

Answer 8

Determine the linear density of atoms (atoms/m) along the [111] direction of gold at 300K.

Answer 9

An eye doctor shines a bright light into a patient's eye. In one to two sentences, explain how the patient's brain perceives the bright light.(2 points) PLEASE ANSWER