The power of flash light is [tex]2.36*10^{-9}\ W[/tex] when light emits [tex]1.4*10^{10}[/tex] photons of wavelength is 490nm for 2.4 seconds.
The fundamental particle of light is both mundane and surprising. What physicists refer to as photons, laypeople may simply refer to as light. Photons are the smallest possible packets of electromagnetic energy as quanta of light.
Given,
The wavelength of photon = 490 nm
Number of photons, n= [tex]1.4*10^{10}[/tex]
The flash light lasts for time ,t =2.4 s
The energy of a single photon can be determined by formula,
[tex]E=\frac{hc}{\lambda}\\\\[/tex]
Where,
h= planck's constant = [tex]6.62*10^{-34}[/tex]
c=speed of light = [tex]3*10^8 m/s[/tex]
\lambda = wavelength of light =490 nm = [tex]490*10^{-9}m[/tex]
[tex]E=\frac{6.62*10^{-34}*3*10^8}{490*10^{-9}}\\\\E=4.05*10^{-19}\ J[/tex]
Then the energy for n photons will be [tex]nE=1.4*10^{10}*4.05*10^{-19}[/tex]
The power of the n photons can be determined by formula,
[tex]P=n*E*t\\\\P=1.4*10^{10}*4.05*10^{-19}\\\\P=2.36*10^{-9}\ W[/tex]
Thus, the power of the flash light is [tex]2.36*10^{-9}\ W[/tex]
To learn more about photons refer here
https://brainly.com/question/12674783
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