Question

Calculate the number of photons emitted each second from a laser pointer. The 17.7 milliwatt laser pointer is green, with a wavelength of exactly 532 nm. Note: to input large numbers (scientific notation) into Canvas, you will need to use "e" For example, 1 billion > 1e9 Note: required precision is 2%.

Answer 1

Answer:

$n = 473.709 *10^{14}$

Explanation:

given data:

power = 17.7 milliwatt

p = 17.7 *10^{-3} watt

wavelength = 532 nm = 532*10^{-9} m

energy of photon $e =h \frac{c}{\lambda}$

h is plank constant = 6.626*10^{-34} JOULE/SEC

C =3*10^8 m/sec

$e = 6.626*10^{-34} * \frac{3*10^8}{532*10^{-9}}$

let n is m=number of photon emiited per sec

we knwo that

p = ne

$17.7 *10^{-3} = n *6.626*10^{-34} * \frac{3*10^8}{532*10^{-9}}$

$n = 473.709 *10^{14}$