The eyes of certain member of the reptile family pass a single visual signal to the brain when the visual receptors are struck by photons of wavelength `850nm`. If a total energy of `3.15xx10^(14)J` is required to trip the signal. What is the minimum number of photons that must strike the receptor?

Answer

`1.35xx10^(5)` photons

Explanation

`:. n xx "Energy of one photon" = "Total energy"`
`nxx(6.6xx10^(-34)xx3xx10^(8))/(850xx10^(-9))=3.15xx10^(14) rArr n=1.35xx10^(5)` photons