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Introduction, Measurement and Estimating. AP Physics B Chapter 1 Notes. Nature of Science. Scientific Method Observation Hypothesis Testing Theory. The School of Athens by Raphael. What is Physics?. From the ancient Greek, phsyis “nature”
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Introduction, Measurement and Estimating AP Physics B Chapter 1 Notes
Nature of Science • Scientific Method • Observation • Hypothesis • Testing • Theory The School of Athens by Raphael
What is Physics? • From the ancient Greek, phsyis“nature” • General analysis of nature to understand how universe behaves
What Will I Need for This Trip? • Working knowledge of basic math • Graphing Skills • SI Units and sig figs • Common Sense • Persistence • Patience My Physics Tool Box
Measurement and Uncertainty • Precision • The repeatability of a number • Also refers to the smallest unit of measurement an instrument can give • Accuracy • How close a measurement is to the true value • Percent Error • Act- Exp / Act
Significant Figures • Dry Rules • Non-Zero Digits • Zeros between sig figs • Zeros right of decimal • Zeros as placeholders • Blah, blah blah • Atlantic-Pacific Method • Decimal Point Absent • Decimal Point Present Lets Practice: http://lectureonline.cl.msu.edu/~mmp/applist/sigfig/sig.htm
SI units for Physics • The SI stands for "Systeme International”. • There are 3 fundamental SI units for LENGTH, MASS, and TIME. • Other quantities are derived. • Other base units are shown Page 10 of Giancoli
Most commonly used prefixes in Physics • Prefixes are added to units to define multiples of ten • You should know giga down to nano Page 9 of Giancoli
Example If a capacitor is labeled 2.5μF(microFarads), how would it be labeled in just Farads? The FARAD is the fundamental unit used for capacitors. 2.5 x 10-6 F Notice that we just add the factor on the end and use the root unit. The radio station XL106.7 transmits at a frequency of 106.7 x 106 Hertz. How would it be written in MHz (MegaHertz)? A HERTZ is the fundamental unit used for frequency. Notice we simply drop the factor and add the prefix. 106.7 MHz
Basic Math Required--Trig • Use SOHCAHTOA in right triangle problems • sinθ = O/H • cosθ = A/H • tanθ = O/A • Pythagorean Theorem c b a a2 + b2 = c2
Basic Math Required--Other • Algebraic manipulation • Quadratic Equation • Logarithms • See Appendix A
Converting Units/Dimensional Analysis Dimensional Analysis is a technique you can use to convert from one unit to another and allows you to check if you used the correct formula. Exercise E p. 11: Would a driver going 15 m/s in a 35 mph zone be speeding? (15 m/s) x (60s/min) x (60min/h) x (1 in/2.54 cm) x (100 cm/m) x (1 ft/12 in) x (mi/5280 ft) = 33.6 mph
Graphing Rules • Independent variable is x-axis • Dependent variable is y-axis • Label everything! • Units and scale! • We will learn to use Excel