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# Chapter 3: Relativistic Mechanics

In introductory physics, we often begin with kinematics and then use those concepts in Newtonian mechanics. We will do something similar here. Now that we understand special relativity and its implications for space and time, we need to examine its implications for mechanics particularly for relativistic momentum and energy. We will also explore measurements of the wavelength and/or frequency of light produced by moving sources (the relativistic Doppler effect).

# Table of Contents

## Sections

- Section 3.1: Exploring Relativistic Momentum.
- Section 3.2: Understanding Mass-Energy Equivalence.
- Section 3.3: Understanding the Energy-Momentum Equation.
- Section 3.4: Exploring Particle Decays.
- Section 3.5: Understanding the Relativistic Doppler Effect.
- Section 3.6: Exploring the Twin Paradox Using the Doppler Effect.

## Problems

- Problem 3.1: Rank the kinetic energy.
- Problem 3.2: One graph correctly shows the total energy of an electron.
- Problem 3.3: Determine the mass of a Sigma particle that decays into a pion and a neutron.
- Problem 3.4: What is the energy required in a proton-proton collision to produce a proton anitproton pair?
- Problem 3.5: Determine the mass of a particle that decays into two photons.
- Problem 3.6: What is the energy of the photon that hits and electron and produces an electron-positron pair?
- Problem 3.7: What frequency does the moving twin observe?
- Problem 3.8: What is the speed of a moving car?