In a photoelecric experiment in which a sodium surface is used, you find a stopping potential of 1.85V for a wavelength of 300nm, and a stopping potential of 0.820V for a wavelength of 400nm. From these data find (a) a value for the Planck constant, (b) the work function for sodium, and (c) the cutoff wavelength for sodium.(adsbygoogle = window.adsbygoogle || []).push({});

I tried solving (a) by stating the following

E=nh*f

h=E/f

h=E/(c/Lambda)

h=e*lamba/c ( i let n = 1)

And we know that K_max=e*delta V, where e is the Elementary charge, and DeltaV is the stopping potential.

I assumed that all the Energy is transffered to K_MAX

thus,

H=e*deltaV*lambda/C

The units end up working out, but the solution is wrong.

Anyone know what am i messing up on?

The rest of the question, i believe i can get once I solve this correctly

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# Homework Help: Stopping voltage.

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