Hi! could anyone help me to solve this problem please. Thank you.

Question

Question:An electron has a speed of 0.68 c.
(a) Find the speed of a proton that has the same kinetic energy as the electron.
(b) Find the speed of a proton that has the same momentum as the electron.

Answer 1

http://en.wikipedia.org/wiki/Kinetic_energy#Relativistic_kinetic_energy_of_rigid_bodies