Photoelectric effect, h/e ratio

[Azndude51]

Homework Statement

From the following graph determine the experimental value of the h/e ratio and the work function of the metal. ( 1 Joule = 6.242 x 1018 eV )

https://chip.physics.purdue.edu/protected/Prelab221img/e9pp41.jpg

The work function Wo in eV from the y-intercept of the stopping voltage Vs vs. frequency f graph = ______ eV

I already found the slope (h/e value) to be 3.73e-15 V*s which is correct according to the the online homework.

Homework Equations

I would assume that all I need is e = 1.60e-19 C to get eV from V.

The Attempt at a Solution

The Y-int appears to be around .64 V (I used this value to help get the slope so it should be correct) so I multiply that by e to get 1.02e-19 eV. However, this answer is not correct, what am I doing wrong?

 

[andrevdh]

You read the y intercept off at $$5 \times 10^{14}\ Hz$$!