A red laser pointer emits light at a wavelength of 488 nm.If the laser emits 7.5 × 10^-4 J of energy per second in the form of visible radiation,how many photons per second are emitted from the laser? A) 4.1 × 10^-19 photons/sec B) 5.4 × 10^-16 photons/sec C) 8.9 × 10¹⁴ photons/sec D) 1.8 × 10¹⁵ photons/sec E) 2.5 × 10¹⁸ photons/sec

Question

Quizplus · Accepted Answer

The energy of a single photon is given by E = hc/λ. Using h = 6.626 × 10^-34 J·s, c = 3 × 10^8 m/s, and λ = 488 nm = 488 × 10^-9 m, we find the energy per photon. Then, divide the total energy emitted per second by the energy per photon to find the number of photons emitted per second.

A Red Laser Pointer Emits Light at a Wavelength of 488