What does it mean to say that momentum is conserved? when momentum or any other object in physics doesn't change..... momentum = momentum before and after the collision. Elastic collision
The 2016 Springfield, Illinois, population is 116,565. There are 1,955 people per square mile (population density). The median age is 38.7. The US median is 37.4. 44.11% of people in Springfield, Illinois, are married. 14.83% are divorced.
Present-day Springfield was first settled by European Americans in the late 1810s, around the time Illinois became a state. The most famous past resident is Abraham Lincoln, who lived in Springfield from 1837 until 1861, when he went to the White House as President.