# Physics 511A, 2014: Chapter 2, Volume 2. Relativistic mechanics

1. Derive the ${\displaystyle v/c\to 0}$ limit of the Hamilton-Jacobi equation.
5. A massive particle of energy ${\displaystyle E_{1}}$ traveling with a velocity ${\displaystyle v}$, not necessarily small relative to the speed of light, emits a photon of the energy ${\displaystyle E_{2}}$ in a certain direction ${\displaystyle \theta }$ in its rest frame. What is the angle, by which its velocity is deflected in a nonmoving reference frame?