Formula: Photoelectric Effect Energy Frequency Voltage Planck's Constant
$$W ~=~ h \, f ~-~ e \, U_{\text G}$$
$$W ~=~ h \, f ~-~ e \, U_{\text G}$$
$$f ~=~ \frac{W ~+~ e \, U_{\text G}}{h}$$
$$U_{\text G} ~=~ \frac{h \, f ~-~ W}{e}$$
$$e ~=~ \frac{h \, f ~-~ W}{U_{\text G}}$$
$$h ~=~ \frac{W ~+~ e \, U_{\text G}}{f}$$
Work function
$$ W $$ Unit $$ \mathrm{J} = \mathrm{Nm} = \frac{ \mathrm{kg} \, \mathrm{m^2} }{ \mathrm{s}^2 } $$
Work function is the energy that must be spent to eject an electron from a solid (e.g. from a metal plate). It is usually expressed in units of "eV" (electronvolt).
Frequency
$$ f $$ Unit $$ \mathrm{Hz} = \frac{ 1 }{ \mathrm{s} } $$
Frequency of the light with which, for example, a metal plate is illuminated.
Stopping voltage
$$ U_{\text G} $$ Unit $$ \mathrm{V} = \frac{ \mathrm J }{ \mathrm C } = \frac{ \mathrm{kg} \, \mathrm{m}^2 }{ \mathrm{A} \, \mathrm{s}^3 } $$
Back voltage is the voltage between two capacitor plates. This voltage is adjusted so that the electrical energy \(e \, U_{\text G} \) exactly compensates the kinetic energy of the ejected electron.
Elementary charge
$$ e $$ Unit $$ \mathrm{C} = \mathrm{As} $$
The elementary charge is a physical constant and is the smallest, freely existing electric charge in our universe. It has the exact value:
$$ e ~=~ 1.602 \, 176 \, 634 ~\cdot~ 10^{-19} \, \mathrm{C} $$
Planck's Constant
$$ h $$ Unit $$ \mathrm{Js} $$
Planck's constant is a physical constant and has the value:
$$ h ~=~ 6.626 \, 070 \, 15 \, \cdot \,10^{-34} \, \mathrm{Js} $$