I need help with this problem so please help me.
1. A certain photoelectric surface has a threshold frequency of 6.2*10^14 Hz.
A. How much kinetic energy is required to produce an electron emission?
B. if the surface is illuminated with light that has a frequency 7.1*10^14 Hz, what is the kinetic energy of the emitted electron in joules?
C. What is the kinetic energy of the emitted electron in electron-volts?