The stopping potential for photoelectrons ejected from a surface by 375 mm photons is 1.870 V. Calculate the stopping potential for 600 nm photons .

Explanation

Strategy : We will use energy conservation to find the work function and then use that to find the stopping potential for 600 nm photons, the target variable .
The stopping potential energy is equal to photon's energy minus the work function :
`eV_0=hf-phi`
The work function is found from the 375 nm photon response .
Now, `phi="hc"/lambda-eV_0`
`=((6.626xx10^(-34) J.S)(3.00xx10^8 m//s))/((375xx10^(-9)m))-(1.6xx10^(-19)C)(1.870 V) `
`=2.31xx10^(-19) J`=1.44 eV
For the 600 nm photons , we find the stopping potential from
`eV'="hc"/(lambda')-phi`
`=1.00xx10^(-19)` J.
The stopping potential for the 600 nm photons is then
`V_0^'=(1.00xx10^(-19)J)/(1.6xx10^(-19)C)`=0.627 V