Achieve Question 7

[gary_vernes]

Hello, I am having some trouble on this question. It states:
As you may well know, placing metal objects inside a microwave oven can generate sparks. Two of your friends are arguing over the cause of the sparking, with one stating that the microwaves "herd" electrons into "pointy" areas of the metal object, from which the electrons jump from one part of the object to another. The other friend says that the sparks are caused by the photoelectric effect. Prove or disprove the latter idea using basic physics.

a.] Suppose the typical work function of the metal is roughly 3.30×10−19 J. Calculate the maximum wavelength in angstroms of the radiation that will eject electrons from the metal."

For this part I've been using the work function as E of photon, since that is the minimum energy needed. So I've been doing lambda = hc/E, then converting to Angstroms, but it hasn't been working. Could someone give me some insight on how to solve this problem? Thanks!

[Max Lee Dis3B]

Hi. The equation you provided should work. Wavelength = ((6.626 x 10^-34 J*S)(3 x 10^8 M*S))/(3.3 x 10^-19 J) = 6.02 x 10^-7 m which would equal 6020 Angstroms.