Question

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

Explanation:

Momentum conservation requires a closed system (no mass exchange) and an isolated system (no external forces). Open systems (mass exchange) or systems with external influences (like added energy, temperature changes affecting forces) don't conserve momentum.

Answer:

closed system and isolated system