Photoelectric effect and cutoff frequency

[lha08]

Homework Statement

I was just wondering that when I have a graph of the Stopping Potential versus Frequency of the light. How can I find the value for the cutoff frequency?
Wavelength Vo
160 nm 2.99 V
53 nm 19.18 V
80 nm 11.00 V
160 nm 2.93 V
187 nm 1.92 V

Homework Equations

The Attempt at a Solution

 

[Dadface]

What attempt have you made?

 

[rock.freak667]

Write down the equation for the photoelectric effect and then use the fact that the stopping potential is the work done in stopping the electrons from having any kinetic energy.

 

[lha08]

What attempt have you made?

well i found the theoretical value of the slope: 4.14125 X 10^-15 Js/C and the actual value of the slope: 3.9512 X 10^15 J s/C but don't know how to use them to find the answer

 

[Dadface]

As rockfreak advised write down the equation.Next rearrange it to make V the subject of the equation and then compare what you have to the equation of a straight line.By comparison you should be able to identify what the gradient of the graph represent and what the intercepts on the y and the x-axis represent.

 

[lha08]

As rockfreak advised write down the equation.Next rearrange it to make V the subject of the equation and then compare what you have to the equation of a straight line.By comparison you should be able to identify what the gradient of the graph represent and what the intercepts on the y and the x-axis represent.

does the y intercept of the graph represent the work function?

 

[Dadface]

Did you plot V on the y axis?If so the intercept has the units of volts ie joules per coulomb.The work function has the units of Joules so what could the intercept represent?Also, look at the intercept on the x axis.