Calculate the threshold frequency for a metal with a work function of 3eV

The equation for work function is: W = hf

So, this is rearranged to: f = W/h where h is planck's constant.

Therefore, if we know the work function then we can work out the threshold frequency.

Don't forget to convert 3eV into J. 1eV = 1.6 x 10^{-19} J.

f = (3 x 1.6 x 10^{-19})/(6.63 x 10^{-34})
f = 7.24 x 10^{14} Hz

AW

Related Physics A Level answers

All answers ▸

How can we derive the 'suvat' equations of motion v=u+at and s=(u+v)t/2


A nucleus of the stable isotope Pb(208,82) has more neutrons than protons. Explain why there is this imbalance between proton and neutron numbers by referring to the forces that operate within the nucleus.


Electrons moving in a beam have the same de Broglie wavelength as protons moving in a separate beam. The proton beam moves at a speed of 3.1 x 10^4 m/s. What is the speed of the electrons?


What is a neutrino?