What is the Maximum Velocity of Electrons Ejected from Copper by 200 nm Light?

[eq123]

i've been trying to figure out this problem..

The longest wavelength of light that causes electrons to be ejected from the surface of a copper plate is 243 nm. What is the maximum velocity of the electrons ejected when light of wavelength 200. nm shines on a copper plate?

the answer is 6.22 × 105 m/s

any ideas?

 

[espen180]

Read about photoelectric effect.

E_k=hf-φ

Where φ is the work function, the lowest energy that must be supplied to tear off an electron, and hf>φ.

 

[alxm]

Read the forum rules!
This isn't the correct board for homework problems. And you should show some attempt to having solved the problem.

 

[eq123]

Ek=hf-φ

thank you.. but how can i relate this to the wavelength concept?

This isn't the correct board for homework problems.

this is not a homework problem.. it is an old exam question..

i would appreciate any additional information..

 

[PhaseShifter]

thank you.. but how can i relate this to the wavelength concept?

f={c\over\lambda}