Relativistic energy Definition and 58 Threads

Hey I have a problem concerning relativistic energy One neutrino has an energy of 10 MeV and a rest mass of 10 eV/c^2. Another neutrino has an energy of 30 MeV and a rest mass of 10 eV/c^2. Calculate the difference in time that the two particles arrive at Earth if they are emitted from a...

A particle of initial kinetic energy T[SIZE="1"]0 and rest energy E[SIZE="1"]0 strikes a like particle at rest. The initial particle is scattered at an agle theta to its original direction. Show that the final kinetic energy T is T = T[SIZE="1"]0cos2(theta)/(1+...

how do we measure the relativistic energy of a tardyon?

a little rough on this simplification, is this correct? solving for "u" E = mc^2 / (root)(1-u^2/c^2) (root)(1-u^2/c^2) = mc^2/E 1 - u^2/c^2 = (mc^2/E)^2 1 = (mc^2/E)^2 + u^2/c^2 c^2 = (mc^2/E)^2 (c^2) + u^2 -> (sq root everything) u = c - mc^3/E pretty bad i don't...

all speed are relative to the observer, but if we have 2 planets with inteligent beings and for one of them all the objects in the universe seem to move just a bit slower than the other planet, wouldn't it then be less matter and energy in thge universe for those biengs? and with finite amount...

can anyone explain to me wha relativistic is?

A pion at rest (m_pi = 273m_e) decays to a muon (mass = 207m_e and an antineutrino (mass = 0). Find the kinetic energy of the muon and the energy of the antineutrino in electron volts. How am I supposed to start this problem? ANy help would be great...thx!

I am now currently using an introductory modern physics textbook but they did not give me the derivation for relativistic KE for a moving object which is \gamma mc^2 . Is the derivation too difficult to be put in the introductory text?? Anyway, what is its derivation? Thanks alot.