Basics of Physics

Science Study of energy flow and energy transfer through living and non-living systems

Physics Study of matter, energy and space and the relationships between them Explain how the physical world works 3 major areas Concepts & calculations

Major Topic Areas Kinematics & Mechanics – motion caused by forces Waves –Sound, light and optics Electricity & Magnetism –fields, electric current, circuits, electromagnetism

Concepts & Calculations Concepts –Fundamental laws, theorems and principles which explain and govern physical phenomena and interactions Calculations –Mathematical formulas & equations (all algebraic) which quantify the relationships between variables

Problem Solving Procedure Read the problem carefully Draw a simple diagram Write down all numerical data, both given and assumed Write down what problem is asking you to solve Determine equation or formula required for solution – write it down Rewrite equation with #’s inserted Perform arithmetic & algebraic operations – show full process in homework & on tests Include correct units with answer

Notebook Homework Format # 3 11) tan 2=192/x x =192/tan2 11) 5.5 km Answers and process for Practice Problems in back of textbook transparency

Chapter 1 A Physics Toolkit

SI Units of Measurement Base units –Lengthmeter(m) –Masskilogram(kg) –Timesecond(s) All lab measurements and answers to problems must have a number and correct units Smoots

SI Metric Prefixes Factors making unit << 1 Example – micro  10  6  g – milli m10  3 ms – centic10  2 cm Factors making unit >> 1 – kilo k10 3 kg – mega M10 6 MHz – gigaG10 9 GByte

Unit Conversions Unit cancellation method – dividing identical units = 1 Create unit pathway (example on board) Determine correct conversion factors to use Insert #’s next to units Convert 10 mm to m(board) Convert 50 km/hr to m/s

Graphing Data animation clip 1-3 line of best fit

1.Determine which is independent variable (you control) and dependent variable (you measure) 2.Label x axis with independent variable – NAME & UNITS 3.Label y axis with dependent variable – name & units 4.Determine total range of data for x axis: 0 to max value. Divide this into equal increments so that most of axis is used. Spread out the data 5.Determine how many divisions (boxes) on x axis will represent that increment. Increments must be equal for the entire axis. Never plot data points on the axis. 6.Repeat steps 4,5 for y axis. Spread out the data. 7.Divisions do not have to be the same on both axes. Creating a Scientific Graph

Scientific Graphs 8. Do not put breaks in the numbers on either axis – always start at 0 and have continuity of numbers from 0 to maximum value on that axis 9. Determine if origin (0,0) is valid even though not measured. Plot if valid. 10. Plot each data point – neatness counts – pencil recommended. Data point labels not necessary 11. Draw best fit line or smooth curve that fits the data – DO NOT CONNECT DOT-TO-DOT!! You may be using this best fit line or curve for calculations and conclusions. 12. No computer generated graphs will be accepted. Do them by hand on the graph sheets given in lab report.

Linear relationship as independent variable increases the dependent variable also increases at a constant rate straight line equation form: y=mx+b calculate slope using the value of the rise and run include correct units never calculate slope using only

LINE OF BEST FIT       approximately as many data points above the line as below the line GREEN line is line of best fit can use it to calculate slope RED line is incorrect don’t connect the dots it is not a line x y

Quadratic relationship as the independent variable increases the dependent variable increases at an ever-growing rate shape of graph is a parabola Red line is NOT correct – this is NOT a line of best fit equation form: y=ax 2 +bx+c

Inverse relationship as the independent variable increases the dependent variable decreases NOT exponential or quadratic shape is hyperbola equation form: example on board

Physics Lab Experiments Safety is #1 priority Any equipment loss or breakage at a table due to carelessness will result in detention for all bench members Lab days are good days not play days Always start by reading Introduction and then Procedure, do not start at Data Table first. Reading and following directions is very important Complete all data collection before beginning calculations or graphing Lab experiments are not tests. Mr. B will answer questions about procedure AFTER you have read, discussed and thought about the instructions

Lab experiments Communication & cooperation –work as a team; allow multiple members to make measurements; should not have 1 worker and 3 spectators –question and talk to each other –double check calculations if time permits –help each other to get best results possible –listen carefully and take notes during Mr. B’s preview in class No lab book; lab sheets given out on day of lab; only one copy per person Pencils highly recommended; points deducted for sloppy lab reports Clean up and return lab bench to original condition Lab reports ALWAYS due at the beginning of the next class