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.
Mexico Population (LIVE) The current population of Mexico is 130,485,984 as of Saturday, September 2, 2017, based on the latest United Nations estimates. Mexico population is equivalent to 1.73% of the total world population. Mexico ranks number 10 in the list of countries (and dependencies) by population. The population density in Mexico is 67 per Km2 (174 people per mi2). The total land area is 1,943,082 Km2 (750,228 sq. miles) 78.4 % of the population is urban (102,122,953 people in 2017) The median age in Mexico is 27.8 years.