- #1
Understanding the Energy of a Photon: A Closer Look at the Underlying Formula
In summary, the formula for calculating the energy of a photon is E = hf, where E is the energy in joules, h is Planck's constant, and f is the frequency of the photon. The energy of a photon is directly proportional to its frequency, and cannot be negative. It is typically measured in joules (J). Planck's constant is a fundamental constant in quantum mechanics that relates the energy of a photon to its frequency and is crucial in understanding the behavior of light and other electromagnetic radiation.
- #2
Drakkith
Mentor
- 23,094
- 7,504
No, we can and have measured this as far as I know.
- #3
AyoubEd
- 10
- 2
I think i got it
E=h.v
-De broglie : p=h/(the wace longitude:L)
hence:
E=h.c/L=p.c
E=h.v
-De broglie : p=h/(the wace longitude:L)
hence:
E=h.c/L=p.c
- #4
jtbell
Staff Emeritus
Science Advisor
Homework Helper
- 15,993
- 6,563
For relativistic particles, the general relationship between energy, momentum and mass is $$E = \sqrt {(pc)^2 + (mc^2)^2}$$ where m is the invariant mass (often called the "rest mass"). For photons, m = 0 which leads to E = pc.
- #5
AyoubEd
- 10
- 2
thanks a lot @jtbell 
FAQ: Understanding the Energy of a Photon: A Closer Look at the Underlying Formula
What is the formula for calculating the energy of a photon?
The formula for calculating the energy of a photon is E = hf, where E is the energy in joules, h is Planck's constant (6.626 x 10^-34 joule seconds), and f is the frequency of the photon in hertz.
How does the energy of a photon relate to its frequency?
The energy of a photon is directly proportional to its frequency. This means that as the frequency increases, the energy of the photon also increases.
Can the energy of a photon be negative?
No, the energy of a photon cannot be negative. It is always a positive value, and the amount of energy is determined by the frequency of the photon.
How is the energy of a photon measured?
The energy of a photon is typically measured in joules (J), which is a unit of energy in the International System of Units (SI).
What is the significance of Planck's constant in the formula for the energy of a photon?
Planck's constant, represented by the symbol h, is a fundamental constant in quantum mechanics that relates the energy of a photon to its frequency. It allows us to calculate the amount of energy carried by a photon, and is a crucial component in understanding the behavior of light and other electromagnetic radiation.