## DeBroglie confirmation.

$\lambda=\frac{h}{p}$

405404782 Gabriel Rigole 4F
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Joined: Sat Aug 17, 2019 12:18 am

### DeBroglie confirmation.

So DeBroglie's equation only applies when mass is present, but can not be used when there is no mass? Is this why it does not apply to light?

Chem_Mod
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### Re: DeBroglie confirmation.

That is correct. The DeBroglie equation is only used for particles with rest mass. To find the wavelength of light, you would use $c = \lambda \nu$

KDang_1D
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### Re: DeBroglie confirmation.

Yes, an object must have rest mass in order to use the DeBroglie equation. This is shown in the equation, λ = h/p = h/(mv), which needs mass (m) to calculate the momentum.