9. define and give an example of a system? distinguish among the input flow (throughput), and output of a system wny
are scientific models useful? what is feedback? what is a feedback loop? distinguish between a positive feedback loop
and a negative corrective) feedback loop in a system, and give an example of each. distinguish between a time delay
and a synergistic interaction (synergy) in a system and give an example of each. what is a tipping point?