Numerical Problems | Chapter 13 | Relativity | Physics 11th | National Book Foundation 2025

For latest videos, click on the following link: https://whatsapp.com/channel/0029VaGr... Calculate the equivalent energy of an electron having rest mass 9.11×〖10〗^(-31) kg. The length of a spaceship is 100m long. What will be its length if the spaceship moves with a speed of 0.99c. Particle called π-mesons are produced by accelerator beams. If these particles travel at 2.70×〖10〗^8 m/s and live 2.60×〖10〗^(-8) s when at rest relative to an observer. How long do they live as viewed in the laboratory? A neutral π-meson lives 1.40×〖10〗^(-16) s as measured in the laboratory, an 0.840×〖10〗^(-16) s when at rest relative to an observer, what is its velocity relative to the laboratory?