E=h Nu
Most recent answer: 10/22/2007
Q:
Hey, I got a question for you. Please solve it and answer it back with the right answer. It’s about Photon Energy. What is the real formula for the E=hv ? I mean, every site I look at, has different formulas and I don’t know who to trust cept’ you, cuz you seem smart. Anways, What does the "h" equal to?
- Chris (age 17)
Baltimore
- Chris (age 17)
Baltimore
A:
Chris- First, a piece of advice. Don’t trust anyone too much. The Royal
Society motto is ’Nullius in Verba’, which means something like
’nothing by say-so’.
Anyway, here’s what we say. The photon energy is the light frequency times Planck’s constant. The frequency is often given the name "nu", a Greek letter whch looks a lot like a "v". Planck’s constant is usually called "h". Its value is about 6.626*10^-34 Joules/ Hz. A Joule is a unit of energy, and a Hertz is a unit of frequency, so when you multiply a frequency by h you get an energy.
I’m a little surprised that you found any formulas around that disagree with this. Maybe they just wrote the same thing using different symbols. (sometimes you see E = hbar*omega, but this is really the same formula. Omega is just customarily nu times two times pi, and hbar is h divided by two pi. It’s written as a lowercase h with a little slash through the vertical line. A lowercase Greek omega looks a bit like a "w" with rounded lines on the bottom).
Mike W. (and Tom)
Anyway, here’s what we say. The photon energy is the light frequency times Planck’s constant. The frequency is often given the name "nu", a Greek letter whch looks a lot like a "v". Planck’s constant is usually called "h". Its value is about 6.626*10^-34 Joules/ Hz. A Joule is a unit of energy, and a Hertz is a unit of frequency, so when you multiply a frequency by h you get an energy.
I’m a little surprised that you found any formulas around that disagree with this. Maybe they just wrote the same thing using different symbols. (sometimes you see E = hbar*omega, but this is really the same formula. Omega is just customarily nu times two times pi, and hbar is h divided by two pi. It’s written as a lowercase h with a little slash through the vertical line. A lowercase Greek omega looks a bit like a "w" with rounded lines on the bottom).
Mike W. (and Tom)
(published on 10/22/2007)