1. The problem statement, all variables and given/known data A charged particle is observed to have a total energy of 0.642 MeV when it is moving at 0.700c. If this particle enters a linear accelerator and its speed is increased to 0.980c, what is the new value of the particle's total energy? 2. Relevant equations Rest mass energy: E0=mc2 Kinetic energy: K=([tex]\gamma[/tex]-1)mc2 Total energy: E=E0+K 3. The attempt at a solution I tried to solve for the rest mass energy using the original speed and total energy, but got stuck. I also tried to set up a ratio of old total E on top of new total E, but that didn't give me the correct answer. Can anyone help? Thanks!