A laser emits a pulse of light that lasts 10 ns. The light has a wavelength of 690 nm, and each pulse has an energy of 480 mJ. How many photons are emitted in each pulse? (c = 3.0 × 10⁸ m/s, h = 6.626 × 10^-34 J ? s) A)1.7 × 10¹⁸ B)2.1 × $10 ^ { 27 }$ C)2.6 × $10 ^ { 37 }$ D)3.1 × $10^{43}$

Question

Quizplus · Accepted Answer

To find the number of photons, first calculate the energy of a single photon using E = hc/λ. Then, divide the total energy of the pulse by the energy of a single photon. This gives approximately 1.7 × 10^18 photons.

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A Laser Emits a Pulse of Light That Lasts 10 $10 ^ { 27 }$