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How many photons are produced in a laser pulse of 0.418 J at 633 nm?... I got 2.756635753 x 10^36

Is that right?

User Kenley
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1 Answer

4 votes

That is not right. There are 1.33 × 10¹⁸ photons .

Energy of one photon

E = hf = hc/λ = (6.626 × 10⁻³⁴ J·s × 2.998× 10⁸ m·s⁻¹)/(633 × 10⁻⁹ m)

= 3.138 × 10⁻¹⁹ J

Number of photons

No. of photons = 0.418 J × (1 photon/3.138 × 10⁻¹⁹ J) = 1.33 × 10¹⁸ photons

User Geraldo Neto
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6.3k points