1 Why Study Physics? 3, 4Why Study Physics? Mathematics and Physics Speak 5, 6Mathematics and Physics Speak Theories and Laws Scientific Notation and Significant Figures 16+Scientific Notation and Significant Figures Units Dimensional Analysis Problem Solving Techniques 29Problem Solving Techniques Approximations 30Approximations Graphs 32-33Graphs HK: CQ: 1, 8. P: 1, 3, 5, 13, 25, 39, 49. Chapter 1: Introduction

2 Scientific Theory A model for explaining phenomena that is simple yet predicts a broad range. Criterion: Testable Accurate (not perfect) 2

3 Law A scientific law is a statement describing natural behavior which has a history of scientific replication. Law = describing Theory = explaining Describing is easier than explaining! Laws usually come first. E.g. Boyle’s Law (1662), Bernoulli’s Kinetic Theory of gases (1740). 3

44 SI Base Units meter (m) kilogram (kg) second (s, sec) ampere (A) kelvin (K) mole (mol) candela (cd)

5 Prefixes for SI Units convenient shorthand for powers of 10 examples: m = e.g. millimeter c = e.g. centimeter k = 10 3 e.g. kilometer

66 Other Common Units foot:3.28ft = 1m mile:1mi = 1609m hour: 1h = 3600s /

7 Significant Figures (s.f.) trailing 0’s count, e.g leading 0’s not counted, e.g more s.f. implies more precision s.f s.f s.f s.f s.f s.f.

8 Calculating with Significant Figures

99 Unit Analysis calculation and comparison of units Given: v = at [v] = m/s [t] = s [v] = [a][t] m/s = [a]s [a] = m/s/s

10 Dimensional Analysis units replaced by “dimensions” e.g. meter = L, seconds = T unit-independent e.g. [velocity] = L/T

11 Converting Units

12 Problem Solving write key data as you read mark unknowns with “?” double check each value use SI values, e.g. 5cm  0.05m sketch physical situation write equations solve, consider, read question again

13 Summary Unit and Dimensional Analysis Metric Prefixes -9 to +9 Unit Conversions Problem Solving

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16 Significant Figures (s.f.) estimate of measurement precision trailing 0’s count (3.00) leading 0’s not counted (0.004) s.f.3.0/1.56 = s.f /1.56 = s.f s.f = s.f = s.f.

17 Common Prefixes PrefixSymbolPower of 10 gigaG10 9 megaM10 6 kilok10 3 centic10 -2 millim10 -3 microμ10 -6 nanon10 -9