Question

Determine the number of photons emitted per second by a laser that emits red light of wavelength 650 nm and has a power output of 2.00 x10 w.

(a) 6.54x10's photons/s

(b) 5.23x10" photons/s

(c) 3.834 x 1016 photons/s

(d) 9.29x1044 photons/s​

Answer 1

Answer:

a) 6.54 x 10

Explanation: The photon energy equivalent to speed times the planck constant divide by λ(wavelength) of photon.

formula used (e=nhc/ λ)

given power output 2.00 x10 w

λ= 650 nm

h=6.26x10⁻³⁴

c= 3x10⁸

put value in formula

2.00x10= nx (6.6x10⁻³⁴) x 3x10⁸/ 650x10⁻⁹

n=2x10 x 650x 10⁻⁹/ 19.8 x 10⁻²⁶

n= 6.54x10's photon/s.