Finding work function without the mass of electron

[Dr_Beula_PhD]

Hey there

 

Just wondering if anyone can help me,I've had a question about work function of a metal with a certain wavelength and velocity given but no mass of electron,can this be done???

 

Cheers

 

Beula

 

P.S anyone into forensic science?

[swansont]

Velocity of what? I don't think you've given enough information to decide what question is being asked. If the wavelength given is the threshold or cutoff wavelength, then [math]E=\frac {hc}{\lambda}[/math]

The mass of the electron is not needed in this case. But it depends on what you've been given.

[Dr_Beula_PhD]

Ok here's the question:

Light of wavelength 0.50 x 10-6 m falls on a metal surface and results in

emission of electrons of velocity 6.0 x 105 m s-1. Calculate the work

function of the metal in Joules per electron.

[swansont]

Ok here's the question:

Light of wavelength 0.50 x 10-6 m falls on a metal surface and results in

emission of electrons of velocity 6.0 x 105 m s-1. Calculate the work

function of the metal in Joules per electron.

 

OK' date=' you do need the mass so you can calculate the KE of the electron. Typically that's assumed to be known, as it's a constant. 9.11 x 10[sup']-31[/sup] kg

[Dr_Beula_PhD]

Ah fantastic!!Thank you very much:-) I can now relax and if a question comes up like this in my exam I should be able to do it!

 

Beula

[swansont]

Post your work if you'd like for me/us to double-check it.

[Dr_Beula_PhD]

Ah cool!Thank you very much:-)

That question was on one of the past papers for my course and while revising came across it and was abit stuck!

I do have more projects planned though so when I get near to finishing them I shall post them up if thats cool?