Recall that the theory of special relativity says that weird things happen at high speeds: time slows down length contracts Are there any other variables that change? Consider momentum and mass... Relativistic Momentum - subatomic particles are zipping about at relativistic speeds (v> 0.7c) - momentum is given by p'- mv - m, is the rest mass (the mass measured by the observer at rest) Ex/l Linear accelerators accelerate charged particles to nearly the speed of light. A proton is accelerated to 0.999 994c. (a) Determine the magnitude of the relativistic momentum. (b) Compare the relativistic and classical momentum of the proton. Note: p' = 'Po (mv)' = y(mv). m = Y = - but v' = Vo as v - c, the mass becomes infinitely heavy infinitely heavy objects require infinite amount of energy to move them nothing can move faster than c also, mass can't be smaller than 1 unit problem: conservation of energy?