Photoelectric effect and mercury

[stickplot]

Homework Statement

a. Does the photoelectric effect take place if mercury is illuminated with UV light with a wavelength λ = 300 nm? The cutoff wavelength for mercury is 250 nm.

Homework Equations

ft= WF/h(planks constant)
E=h(f)

The Attempt at a Solution

im not sure how to start this because the work function is not given and neither is the frequency i know that i can get the work function if i have the frequency by multiplying it with planks constant, but I am not sure how to get it with just the wavelength.

 

[mgb_phys]

You are given the cut off wavelength, and wavelength and frequency are related.
But you don't need to calculate anything - just a bit of reasoning.

Your light is longer wavelength than the cut off, is this higher or lower energy?
Which would it have to be to eject an electron?

 

[stickplot]

o ok, so this means that the energy is lower because the frequency would be lower, so photoelectric effect would not take place. is that right?

 

[mgb_phys]

Correct, longer wavelength = lower frequency = lower energy
So no emmission

 

[stickplot]

alright thanks

 

[ladiebug511]

How would you calculate the cutoff frequency of an x-ray tube operating at 44kV? I am using frequency = work function/h. I have (44000eV x 1.602E-19J)/1.626E-34 but my answer is wrong. I'm thinking that I converted kV to eV incorrectly, but I'm not sure.
Thanks.