Physics 1000 Lecture Notes 001/002 PDF

Physics 1000 – 001/002 Introduction – Physical Standards and Units  Individual Lecture Sequence Review previous homework/exam New material Read chapter to reinforce lecture Homework (Blackboard) What is Physics?  What is Physics? Physi...

Physics 1000 – 001/002 Introduction – Physical Standards and Units  Individual Lecture Sequence Review previous homework/exam New material Read chapter to reinforce lecture Homework (Blackboard) What is Physics?  What is Physics? Physics is the study of the physical world  What is Physics? Physics is the study of the physical world This is done by finding patterns, and attempting to predict future behavior  Scientific Laws When enough experiments have become universally accepted within the scientific community, it becomes known as a law Scientific law, physical law, and law of nature are all used interchangeably Even long-held laws can be disproven if new evidence is presented Experimental results can never prove an idea, they can only disprove it A scientific law must be testable It must make predictions that can be tested and possibly disproven  Physical Standards and Units When measuring something (distance, time), it helps to have a common frame of reference Units are standards we agree on in order to measure other things consistently Different systems use different units for measuring the same quantity For example, the meter and the foot both measure distance This class will primarily use SI units Le Système International d’Unités, or International System of Units As units get more complex in physics, the US system becomes harder to use  Area Unit Comparison (US/SI) Area is a distance multiplied by another distance Acre Traditionally defined as the area of one chain (66 feet) by one furlong (10 chains) 66’ x 660’ = 39600 square feet Square kilometer One kilometer by one kilometer 1000 meters by 1000 meters 1,000,000 square meters  Units Quantity Unit (SI) Unit (US) SI to US US to SI Length Meter (m) Foot (ft) Multiply by 3.281 Divide by 3.281 Mass Kilogram (kg) Pound (lb) Multiply by 2.205 Divide by 2.205 Time Second (s) Second (s) Force Newton (N) Pound force (lbf) Divide by 4.448 Multiply by 4.448 Energy Joule (J) Foot-pound (ft*lb) Divide by 1.356 Multiply by 1.356 Current Ampere (A) Ampere (A) Temperature Kelvin (K) Degree Fahrenheit (°F)  Metric Prefixes Prefix Symbol Short Form Value Common Name peta- P 10^15 1,000,000,000,000,000 quadrillion tera- T 10^12 1,000,000,000,000 trillion giga- G 10^9 1,000,000,000 billion mega- M 10^6 1,000,000 million kilo- h 10^3 1,000 thousand 10^0 1 one centi- c 10^-2 0.01 hundredth milli- m 10^-3 0.001 thousandth micro- μ 10^-6 0.000 001 millionth nano- n 10^-9 0.000 000 001 billionth pico- p 10^-12 0.000 000 000 001 trillionth femto- f 10^-15 0.000 000 000 000 001 quadrillionth  Scientific Notation A way to express very large (or very small) numbers conveniently Written as , where n is an integer and 400 becomes 1024 becomes 80,000,000,000 becomes 0.000000006 becomes Order of magnitude is a concept used to discuss the scale of numbers in relation to one another Two numbers are "within an order of magnitude" of each other if their ratio is between 1/10 and 10 3,000,000 (and 30 () are 5 orders of magnitude apart  Homework Read Chapter 1 Questions: 3, 5, 9, 10, 18, 19, 23, 26, 27, 29