• Support PF! Buy your school textbooks, materials and every day products Here!

Photoelectric effect

  • Thread starter Sassenav22
  • Start date
  • #1
30
0

Homework Statement


What potential difference must be applied to stop the fastest photoelectrons by a nickel surface under the action of ultraviolet light of wavelength 220 nm? work function of nickel is 5.00eV.


Homework Equations


h[c]/[[tex]\lambda[/tex]] = [tex]\Phi[/tex] + eV


The Attempt at a Solution


h=6.6x10^-34 Js
c=3.0x10^8 m/s
[tex]\lambda[/tex]=200x10^-9 m
[tex]\Phi[/tex]=5.00eV
e=1.6x10^-19
V=?

[6.6x10^-34(3.0x10^8)]/[/200x10^-9] = 5.00 + 1.6x10^-19V
9.9x10^-37 = 5.00 + 1.6x10^-19V
9.9x10^37/5.00 = + 1.6x10^-19V
1.98x10^37 / - 1.6x10^-19 =V
v= 1.23x10^.18m/s

not sure if this is right
 
Last edited:

Answers and Replies

  • #2
kuruman
Science Advisor
Homework Helper
Insights Author
Gold Member
8,915
2,321
You need to convert the work function from eV to Joules before you plug it in.
 
  • #3
Also: really watch your units. As you have the equation solved... you're giving an answer in m/s... which doesn't make any sense. Carry your units along with the math... the problem is looking for a potential difference (and the solution should therefore be in volts).
 

Related Threads on Photoelectric effect

  • Last Post
Replies
6
Views
784
  • Last Post
Replies
0
Views
734
  • Last Post
Replies
3
Views
592
  • Last Post
Replies
2
Views
471
  • Last Post
Replies
8
Views
1K
  • Last Post
Replies
4
Views
2K
  • Last Post
Replies
2
Views
1K
  • Last Post
Replies
1
Views
2K
  • Last Post
Replies
0
Views
216
  • Last Post
Replies
1
Views
4K
Top