In Her Physics Laboratory, Mathilda Shines Electromagnetic Radiation on a Material

Short Answer

In her physics laboratory, Mathilda shines electromagnetic radiation on a material and collects photoelectric data to determine Planck's constant. She measures a stopping potential of $5.82 \mathrm {~V}$ for radiation of wavelength $100 \mathrm {~nm}$ , and $17.99 \mathrm {~V}$ for radiation of wavelength $50.0 \mathrm {~nm} . \left( 1 \mathrm { eV } = 1.60 \times 10 ^ { - 19 } \mathrm {~J} , c = 3.00 \times 10 ^ { 8 } \mathrm {~m} / \mathrm { s } \right)$
(a) Using Mathilda's data, what value does she determine for Planck's constant?
(b) What is the work function of the material Mathilda is using, in electron-volts?