Lectures on Physics has been derived from Benjamin Crowell's Light and Matter series of free introductory textbooks on physics. See the editorial for more information.... 
Home Modern Physics Relativity Examples The correspondence principle for massenergy  
Search the VIAS Library  Index  
The correspondence principle for massenergyShow that the equation E = mγc^{2} obeys the correspondence principle. As we accelerate an object from rest, its massenergy becomes greater than its resting value. Classically, we interpret this excess massenergy as the object's kinetic energy,
Expressing γ as (1  v^{2}/c^{2})^{1/2} and making use of the approximation (1 + ε)^{p} ≈ 1 + pε for small ε, we have γ ≈ 1 + v^{2}/2c^{2}, so
which is the classical expression. As demanded by the correspondence principle, relativity agrees with classical physics at speeds that are small compared to the speed of light.


Home Modern Physics Relativity Examples The correspondence principle for massenergy 