Answer:
The value is [tex]n = 2.347 *10^{17} \ photons[/tex]
Explanation:
From the question we are told that
The amount of power delivered is [tex]P = 4.20 \ M W = 4.20 *10^{6} \ W[/tex]
The time taken is [tex]t = 16.0ns = 16.0 *10^{-9} \ s[/tex]
The wavelength is [tex]\lambda = 694.3 \ nm = 694.3 *10^{-9} \ m[/tex]
Generally the energy delivered is mathematically represented as
[tex]E = P * t = \frac{n * h * c }{\lambda }[/tex]
Where [tex]h[/tex] is the Planck's constant with value [tex]h = 6.262 *10^{-34} \ J \cdot s[/tex]
c is the speed of light with value [tex]c = 3.0*10^{8} \ m/s[/tex]
So
[tex]4.20 *10^{6} * 16*10^{-9}= \frac{n * 6.626 *10^{-34} * 3.0*10^{8} }{694.3 *10^{-9}}[/tex]
=> [tex]n = 2.347 *10^{17} \ photons[/tex]
