Personally, i think being nice and getting along with all our neighbors so they dont have any intentions of bombing us is important.
Definitely not constantly bombing other countries and deposing world leaders we dont like which will cause foreign combatants to employ guerilla tactics (since, america already has a decent military and no one is going to stand infront of the big guns)
its much more complicated than what i mentioned above and you definitely shouldnt copy and paste this, but here's just some suggestions
Answer:
Speed of sound wave v=νλ=2000×0.35=700 m/s
Distance d=1.5 km=1500 m
Time t=vd=7001500≈2 s
<span>Native American Societies thats your answer ...................................................................................................................................................................................</span>