Important Equations

Number of modes per unit frequency per unit volume in 3D black-body/ thermal cavity?

Wave number in terms of modes of thermal cavity?

Frequency of each mode of thermal cavity/ black-body?

Rayleigh-Jeans law (energy density of each mode of thermal cavity/ black-body if average energy of each mode is k_BT and each mode is equally likely to be occupied)?

What is Compton’s formula?

∆λ=

Wavelength and momentum relationship for photons?

p = h / λ

Einstein’s mass-energy equivalence?

E² = p²c² + m_e² c⁴

What is Planck’s law?

E = hv

v = nu (frequency)

Energy-momentum relationship for a photon?

E = pc

Fundamental wave equation?

v = fλ (mechanical waves)

c = vλ (EM waves in a vacuum)

v = nu (frequency)