Momentum is conserved in case of motion under gravity because a object is pulled by the earth and the earth of pulled by the object. The momentum terms of the object and earth cancel each other out as the object has small mass but high velocity and the earth has very high mass and very small velocity in the opposite direction of the velocity of the object.
Southwick, Massachusetts. Southwick is a town in Hampden County, Massachusetts, United States. The population was 9,502 at the 2010 census. It is part of the Springfield, Massachusetts Metropolitan Statistical Area.
There are four electoral wards in Dorchester (North, South, East and West) showing a combined population of 19,060. The town has been growing steadily with 11,620 residents in 1951, 13,740 in 1971 and 15,100 in 1991.