Question

@nincompoop I need your help !

Answer 1

@nincompoop

Answer 2

Assume that 10^-17 J of light energy is needed by the interior of the human eye to see an object. How many minimum photons of green light (wavelength= 310nm). are needed to generate this energy

Answer 3

E(photon) = hc/λ
so...
E(green photon) = (6.63*10^-34 * 3.00*10^8)/(320*10^-9) = 6.216*10^-19 J
Then just divide the total amount of energy you need by the energy of a single photon of green light and that will give you the number of photons required.

Answer 4

Also just a note, 310nm light is between the UV-A2 and UV-B bands of light which do not include visible colours

Answer 5

The options are
(a)14
(b)15
(c)16
(d)17

Answer 6

Calculate what I suggested and you'll have the right answer.

Answer 7

Did you do any conversions between units

Answer 8

Because i need to get the concept

Answer 9

@Silent_Sorrow

Answer 10

Only to put the wavelength into standard dimensions, h is in joule seconds (J*s) c is in meters per second (m/s) and wavelength is in meters (m)
So (J*s*(m/s))/m which simplifies to J

Answer 11

\[\huge \frac{ 6.63*10^{-34} * 3.00*10^8 }{320*10^-9 }\]

Answer 12

= 6.2 *10^ -19

Answer 13

Yes, that's in joules (J) so now divide the total energy needed (10^-17 J) by 6.2*10^-19 and you'll get your answer

Answer 14

16