I am struggling with thie following Physics III ( Modern Physics) question. Could I get your help on it? Q. Cosmic rays collide with atoms or molecules in the upper atmosphere. If a proton moving at 0.70c makes a head-on collision with a nitrogen atom, initially at rest, and the proton recoils backward at 0.63c, what is the speed of the nitrogen atom after the collision? (The mass of a nitrogen atom is about 14 times the mass of a proton.) Hint: you may assume that the nitrogen speed is not relativistic.

I am struggling with thie following Physics III ( Modern Physics) question. Could I get your help on it? Q. Cosmic rays collide with atoms or molecules in the upper atmosphere. If a proton moving at 0.70c makes a head-on collision with a nitrogen atom, initially at rest, and the proton recoils backward at 0.63c, what is the speed of the nitrogen atom after the collision? (The mass of a nitrogen atom is about 14 times the mass of a proton.) Hint: you may assume that the nitrogen speed is not relativistic.