About: http://webisa.webdatacommons.org/176671908

Property	Value
http://www.w3.org/1999/02/22-rdf-syntax-ns#type	http://www.w3.org/ns/prov#Entity
http://www.w3.org/ns/prov#value	Momentum is a vector quantity and under the conditions you state, the momentum is zero before the collision and must also be zero afterwards.
http://www.w3.org/ns/prov#wasQuotedFrom	askthephysicist.com