Ch 2 Measurements and Calculations 2.1 Scientific Method Qualitative: looks like Qualities, descriptions, characteristics Quantitative: numeric values Measurements, counting

System: region of space selected to study/run experiment Observations  hypothesis theory  law Experiments Independent variable: manipulated, “I change” Dependent variable: responding, data collected Constants: controls, keep conditions same Model: visual, verbal, mathematical Explanation of concept

2.2 Units of Measurement SI SI Base Units Metric system Common units Standard measurements SI Base Units m, kg, K, mol

SI prefixes Scientific notation SI derived units Calculat ions

Conversion Factors

2.3 Using Scientific Measurements Accuracy: closeness to accepted/actual value Precision: closeness of measurements to each other

Error in measurement Significant Figures Skill, equipment, calculations Significant Figures Digits known with certainty and one rounded/estimate

Rounding Scientific notation: Solving problems: >5 add 1 <5 same M x 10n M 1-9 and n whole # Solving problems: Analyze Plan Solve Check work

Directly proportional Dividing one by other gives constant value Not all linear plots are directly proportional Line goes through (0,0) Inversely proportional Product is constant Hyperbola Like a see-saw (one goes up the other goes down)