Question

1 what two conditions must exist for momentum to be conserved?
closed system and isolated system
open system and increase in speed
high temperatures and an addition of an energy source
open system and low temperatures

Explanation:

Momentum is conserved when no external net force acts on a system. Closed/isolated systems have no external forces (mass/energy doesn't enter/leave), satisfying this condition. The other options involve external interactions or irrelevant factors that break conservation.

Answer:

A. closed system and isolated system