Answer:
[tex]n=1.34\times 10^5[/tex]
Explanation:
It is given that,
Wavelength of the photon, [tex]\lambda=850\ nm=850\times 10^{-9}\ m[/tex]
Total energy required to trip the signal, [tex]E=3.15\times 10^{-14}\ J[/tex]
Let n is the minimum number of photons that must strike the receptor. Firsly calculating the energy of one photon as :
[tex]E=\dfrac{hc}{\lambda}[/tex]
[tex]E=\dfrac{6.63\times 10^{-34}\times 3\times 10^8}{850\times 10^{-9}}[/tex]
[tex]E=2.34\times 10^{-19}\ J[/tex]
Let n is the number of photons that must strike the receptor. It can be calculated as :
[tex]n=\dfrac{3.15\times 10^{-14}}{2.34\times 10^{-19}}[/tex]
n = 134615.38
or
[tex]n=1.34\times 10^5[/tex]
So, [tex]1.34\times 10^5[/tex] number of photons that must strike the receptor. Hence, this is the required solution.
