List of top Physics Questions on Special Relativity asked in CPET

A particle with rest mass \(m\) is at rest and decays into two particles of equal rest mass \(\tfrac{3}{10}m\), which move along the z-axis. Their velocities are given by:

A meter stick is at an angle of \(45^\circ\) to the \(x\)-axis in its rest frame. The rod moves with a speed of \(\dfrac{c}{\sqrt{2}}\) along the \(+x\)-direction w.r.t. a frame \(S\). The length of the rod in \(S\) is: