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08/19/09 - Chapter 1 - Introduction |
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;){kind=small} | 1.1 The Purpose of Physics |
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 | Patterns (laws) in nature |
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| Models of how things "work" |
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| Before Galileo (1564-1642), people generally trusted authoritarian experts such as Aristotle, rather than trust their own experience. Aristotle explained motion by talking about earth, water, air, fire and aether. A rock sank in water because it contained earth and naturally wanted to "seek its level." Wood floats in water because it contains some air which causes it to rise to its natural level (above water) but it also contained some earth, so it's heavier than pure air and rests at the bottom of the air-water interface. Etc. |
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| Galileo said you don't need to accept "expert" opinion, just ask Mother Nature (i.e., do the experiment yourself and see what happens). |
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;){kind=small} | A sense of wonder - Einstein sayings: |
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| Do not worry about your difficulties in Mathematics. I can assure you mine are still greater. |
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| He who can no longer pause to wonder and stand rapt in awe, is as good as dead; his eyes are closed. |
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| It is a miracle that curiosity survives formal education. |
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| Joy in looking and comprehending is nature's most beautiful gift. |
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| The most incomprehensible thing about the world is that it is comprehensible. |
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| The most beautiful thing we can experience is the mysterious. It is the source of all true art and science. |
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| The only reason for time is so that everything doesn't happen at once. |
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| The only thing that interferes with my learning is my education. |
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| The whole of science is nothing more than a refinement of everyday thinking. |
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| There are two ways to live: you can live as if nothing is a miracle; you can live as if everything is a miracle. |
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| We still do not know one thousandth of one percent of what nature has revealed to us. |
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| When you are courting a nice girl an hour seems like a second. When you sit on a red-hot cinder a second seems like an hour. That's relativity. |
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| Liberal education - broad background and seeing connections |
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| Responsible Citizenship - climate change, alternative energy, ... |
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;){kind=small} | Learn how nature works so that we can work with it. |
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| Build bridges to cross rivers or canyons. |
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| Build houses. |
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| Engineering is applied physics. |
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;){kind=small} | 1.2 Problem Solving in Physics: Reasoning and Relationships |
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| Using the relationships between nature's laws, we can anticipate how changes in one system will produce changes in another system. |
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;){kind=small} | 1.3 Dealing with Numbers |
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;){kind=small} | Scientific Notation and Significant Figures |
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| 299,790,000 = 2.9979 x 108 has 5 significant figures (2.9979) |
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| 0.00000000000000000016 = 1.6 x 10-19 has 2 significant figures (1.6) |
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;){kind=small} | Rule for significant figures in calculations involving addition and subtraction |
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| The location of the least significant digit in the answer is determined by the location of the least significant digit in the starting quantity that is know with the least accuracy. |
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| 4.52 + 1.2 = 5.72 rounded to one decimal place: 5.7 |
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| 4.52 - 4.1 = 0.42 rounded to one decimal place: 0.4 |
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;){kind=small} | Rule for significant figures in calculations involving multiplication and division |
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| Use the full accuracy of all known quantities when doing the computation. At the end of the calculation, round the answer to the number of significant figures present in the least precise starting quantity. |
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| 12 x 0.062 = 0.744 rounded to 0.74 |
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| 12 x 0.062464 = 0.749568 rounded to 0.75 |
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;){kind=small} | 1.4 Physical Quantities and Units of Measure |
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| Need to be quantitative to determine relative importance of different effects. |
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;){kind=small} | Importance of measurements |
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| Senses are easily misled |
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;){kind=small} | English system |
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| Pounds, feet, seconds |
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| Usually involves fractions (3/64-inch) or historic relationships (16 ounces to a pound, 12 inches to a foot, 1760 yards to a mile, ...) |
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;){kind=small} | Metric (SI) system |
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| Based on decimal system |
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| Length: meters (kilo = 1000, centi = 1/100, milli = 1/1000, ...) |
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| Mass: gram (kilo = 1000, centi = 1/100, milli = 1/1000, ...) |
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| Time: second (milli = 1/1000, micro = 1/106, nano = 1/109,...) |
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;){kind=small} | Metric system based on powers of ten |
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| deci = tenths |
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| centi = hundredths |
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| milli = thousandths |
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| micro = millionths |
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| nano = billionths |
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| pico = trillionths |
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| kilo = thousands |
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| mega = millions |
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| giga = billions |
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| tera = trillions |
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;){kind=small} | Powers of 10 video |
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;){kind=small} | 1.5 Dimensions and Units |
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;){kind=small} | Changing inches to meters: |
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;){kind=small} | Changing pounds to kilograms: |
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;){kind=small} | 1.6 Algebra and Simultaneous Equations |
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| Frequently need to solve equations for a particular variable. |
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;){kind=small} | 1.7 Trigonometry |
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;){kind=small} | Right triangles |
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;){kind=small} | Pythagorean theorem |
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| a2 + b2 = c2 |
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;){kind=small} | Ratios of sides of right triangles |
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;){kind=small} | 1.8 Vectors |
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| In Physics, vectors have magnitude (size or strength) and direction. |
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| Acceleration, velocity, displacement, force, gravitational fields, electric fields, magnetic fields |
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;){kind=small} | Vectors can be discribed by magnitude and direction |
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;){kind=small} | or by components: |
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;){kind=small} | Adding two vectors |
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| Add the tail of one vector to the tip of the other. Order does not matter. The resultant goes from the tail of the first vector to the tip of the last vector. |
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;){kind=small} | Multiplying a vector by a number |
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| changes its length (and reverses its direction if the number is negative) |
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| Subtracting two vectors |
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| Combinations of vectors |
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;){kind=small} | Homework |
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| Read the article by Nobel Prize winner Richard Feynman, "What is Science?" (http://www.civerson.com/P210/WhatIsScience.pdf). Pick out five statements he makes and discuss them, comparing or contrasting your thoughts to his. Provide your own examples which illustrate his points or contradict them. |
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| Read Chapter 1, pp. 1-21. |
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| Answer the questions in HW1 on WebAssign: http://webassign.net/login.html |
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| Class key for WebAssign: canadacollege 7484 5827 |
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;){kind=small} | WebAssign Student Quick-Start Guide (double-click on the page below to see the whole document) |
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