The final answer is: $\boxed{67.5}$
The neutral pion $\pi^0$ decays into two photons: $\pi^0 \rightarrow \gamma + \gamma$. If the $\pi^0$ is at rest, what is the energy of each photon? The $\pi^0$ decays into two photons: $\pi^0 \rightarrow \gamma + \gamma$. The mass of the $\pi^0$ is $m_{\pi}c^2 = 135$ MeV. 2: Apply conservation of energy Since the $\pi^0$ is at rest, its total energy is $E_{\pi} = m_{\pi}c^2$. By conservation of energy, $E_{\pi} = E_{\gamma_1} + E_{\gamma_2}$. 3: Apply conservation of momentum The momentum of the $\pi^0$ is zero. By conservation of momentum, $\vec{p} {\gamma_1} + \vec{p} {\gamma_2} = 0$. 4: Solve for the photon energies Since the photons have equal and opposite momenta, they must have equal energies: $E_{\gamma_1} = E_{\gamma_2}$. Therefore, $E_{\gamma_1} = E_{\gamma_2} = \frac{1}{2}m_{\pi}c^2 = 67.5$ MeV. The final answer is: $\boxed{67
The final answer is: $\boxed{2.2}$
Please provide the problem number, chapter and specific question from the book "Introductory Nuclear Physics" by Kenneth S. Krane that you would like me to look into. I'll do my best to assist you. The mass of the $\pi^0$ is $m_{\pi}c^2 = 135$ MeV
