Effect of Light Intensity on Photoelectron Kinetic Energy and Emission Rate

[stickplot]

Homework Statement

A metal gives off photoelectrons with maximum kinetic energy Kmax at the rate of N per second when a beam of light of wavelength λ shines on it. How will Kmax and N change if the intensity (brightness) of light is doubled? Assume 100% efficiency.

Homework Equations

hc/wavelength=? then. P/?=

h=planks constant
c= speed of light
p=power

The Attempt at a Solution

kinetic energy will remain the same
n will double

Im not sure how to do this problem
if the brightness doubles, will the frequency double? or the wavelength?
and I am not sure how that would affect n per second

so what I am basically asking is. Is the intensity of light related to the frequency, and if so, in what way?

 

[Hootenanny]

Homework Statement

A metal gives off photoelectrons with maximum kinetic energy Kmax at the rate of N per second when a beam of light of wavelength λ shines on it. How will Kmax and N change if the intensity (brightness) of light is doubled? Assume 100% efficiency.

Homework Equations

hc/wavelength=? then. P/?=

h=planks constant
c= speed of light
p=power

The Attempt at a Solution

kinetic energy will remain the same
n will double

Im not sure how to do this problem
if the brightness doubles, will the frequency double? or the wavelength?
and I am not sure how that would affect n per second

so what I am basically asking is. Is the intensity of light related to the frequency, and if so, in what way?

Light intensity is a measure of the [time-averaged] energy flux and has S.I. units of W.m^-2. In other words, light intensity is a measure of the average amount of energy passing through the unit surface. In terms of photons, the intensity of light is directly proportional to the number of photons passing through the unit area per unit time.

Perhaps this will help: http://www.Newton.dep.anl.gov/askasci/phy05/phy05113.htm

 

[stickplot]

ok. so does that mean that the photons would double in number since the brightness doubles, and kmax would remain the same.
is this right?

 

[Hootenanny]

ok. so does that mean that the photons would double in number since the brightness doubles, and kmax would remain the same.
is this right?

Sounds about right to me

 

[stickplot]

alright thanks :)