Particle Tracks and Relativity    

    Calculate the Momentum 

1. Calculate the initial momentum of the electron.

2. Calculate the electron speed using p = mv. Does the result seem strange to you? If you know any other way of doing it, do it! If not, go to the next question.

3. Calculate the electron velocity using the relativistic expression for p.

NOTE: In schools, we derive the equation p = qBR using non - relativistic mechanics, but it is also valid in special relativity (provided you do not substitute p for mv). Isn't that curious?