Fundamentally, momentum conservation is linked to invariance under space translations. See Noether's theorem. If you want to find a system that does not conserve momentum you should look for situations where space is not uniform, e.g. balls rolling on the surface of a bowl, a planetary system (when the dynamics of the sun is neglected), etc.
Socorro is a city in Socorro County in the U.S. state of New Mexico. It is in the Rio Grande Valley at an elevation of 4,579 feet (1,396 m). In 2012 the population was 8,906.
As of July 2000, the population of Mexico was estimated to be 100,349,766. This is 19,099,766 more than the 1990 population of 81,250,000, reflecting a ten-year increase of 23.5 percent. In 2000, the birth rate was estimated to be 23.15 per 1,000. This was more than 4 times the death rate of 5.05 per 1,000.