What is the work function of the photoelectric material?

[ikihi]

Homework Statement

Photons with momentum p= 7.88 x 10^-18 strike a photoelectric material which is in the configuration shown in the figure. The cutoff voltage is measured to be V_stop= 1.75 V. What is the work function of the photoelectric material?

Homework Equations

p = E_photon / c
E₀ = (c ⋅ p) - (V_stop ⋅ e)

The Attempt at a Solution

E₀ = (3.00 x 10⁸ m/s)(7.88 x 10^-18 (ev ⋅ s)/nm) - (1.75 V ⋅ 1.602 x 10^-19 J) = 2.36 eV

 

[patric44]

you should convert the speed of light to nm/s to match the momentum unit (ev.s/nm)

 

[ikihi]

you should convert the speed of light to nm/s to match the momentum unit (ev.s/nm)

Thanks for catching that error. The new answer I got is 2.36 eV

 

[patric44]

Thanks for catching that error. The new answer I got is 2.36 eV

you are welcome.

thats still the energy of the photon
subtract that from the ke