## Chapter 1, problem 33

Stephanie H
Posts: 20
Joined: Fri Jun 23, 2017 11:39 am

### Chapter 1, problem 33

The velocity of an electron that is emitted from a metallic surface by a photon is 3.6*10^3 km/s.
a) What is the wavelength of the ejected electron?
b) No electrons are emitted from the surface of the metal until the frequency of the radiation reaches 2.50* 10^16 Hz. How much energy is required to remove the electron from the metal surface?
c) What is the wavelength of the radiation that caused the photoejection of the electron?
d) What kind of electromagnetic radiation was used?

Did anyone get 1.07*10^-17 J for part b? This is what I did to get my answer: (0.5*9.109*10^-31*(3.6*10^6)^2=(6.626*10^-34)(2.50*10^16)-work function

Ricky Z1D
Posts: 20
Joined: Fri Jun 23, 2017 11:39 am

### Re: Chapter 1, problem 33

This was one of the problems done during the Wednesday review session. The answer was 1.66 x 10-17 J. The numbers you multiplied by were exactly what we used, so may be we just rounded it differently.

Stephanie H
Posts: 20
Joined: Fri Jun 23, 2017 11:39 am

### Re: Chapter 1, problem 33

I figured out how you guys got 1.66* 10^-17, (0.5*9.109*10^-31)(3.6*10^3)^2=(6.626*10^-34)(2.50*10^16)-workfunction.

I used (3.6*10^3*10^3) to convert the speed from km/s to m/s, and the equation above just keeps the km/s unit.