## Question about 1.33

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

Joe Rich 1D
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### Question about 1.33

The question asks for the wavelength of an electron that was ejected from a metal surface with a velocity of 3.6 x 10^-3 km/s. I know that one way to solve this is by using the De Broglie equation, but I was just wondering if it was possible to solve this by solving for Kinetic Energy of the electron (KE=0.5mv^2), and plugging this energy into the equation E=vh/λ. Thanks!

Dabin Kang 1B
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### Re: Question about 1.33

The question doesn't ask for the wavelength of an ejected electron. It asks for the wavelength of the photon that caused the ejection of an electron.

Joe Rich 1D
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### Re: Question about 1.33

Part a actually does ask for the wavelength of the electron I think.

Dabin Kang 1B
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### Re: Question about 1.33

Oh, I thought you were asking about part C. You would use $\lambda =\frac{h}{p}$ to solve for the wavelength. How did you get E=vh/λ ?

Joe Rich 1D
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### Re: Question about 1.33

I was wondering if you could use the same type of equation as you do for light to relate energy and wavelength, which is E=hc/λ. But instead of using the speed of light, I would substitute in the velocity of the particle. I wasn't sure whether this was a valid technique or not though.