# Elastic Collision Problem 2

1. Mar 3, 2005

### lookitzcathy

Agh... so I posted a similar question like this yesterday and someone has been so kind enough to help me out, but now I'm stuck on this problem!

In the experimental discovery of the neutron (the electrically neutral "brother" of the proton ) the ratio of the velocity of the recoiling (struck) proton over the velocity of the incident neutron was 1.0245. What was the ratio of the neutron mass over the proton mass? (Assume an elastic head-on collision).

Seems so simple... yet I can't seem to get it :uhh: