Answer: sum of forces is zero
Explanation: acording to the newton first law you can say that the sum of the forces acting over the object is zero no matter the direction of movement
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mario
Your answer is correct: Resident 4 would provide the scientist with the most valid results.
A mercury barometer is a device that is used to measure atmospheric pressure at a location. :)
Some commonly used techniques might be distillation and magnetism.
Distillation is basically a method of separating liquid mixture by basically boiling and condensing the different liquids. Since liquids don't have the same boiling points. one will evaporate first, and the other liquid or liquds will remaim.
Magnetism is a method of separating solid mixtures. One or some solids will get atracted to the magnet and the others will remain. Note that this only works if one of the solids has a magnetical property.
Hope it helped,
Happy homework/ study/ exam!