Introduction to Physics!! Get your notebooks out and ready for notes!!!
ON TARGET WHAT IS PHYSICS? Physics is simply the study of the physical world. Everything around you can be described using the tools of physics. The goal of physics is to use a small number of basic concepts, equations, and assumptions to describe the physical world. Physics
ON TARGET NAMESUBJECTSEXAMPLES MECHANICSmotion and its causesfalling objects, friction, forces spinning objects THERMODYNAMICSheat and temperaturemelting and freezing processes, engines, refrigerators VIBRATIONS AND WAVESspecific types repetitive motion springs, pendulums, sound OPTICSlightmirrors, lenses, color, astronomy ELECTROMAGNETISMelectricity, magnetism and light electrical charge, circuits, magnets RELATIVITYparticles moving at any speed particle collisions, particle accelerators, nuclear energy MODERN PHYSICSwave-particle dualityquantum mechanics, particle physics
ON TARGET Laws vs. Theories A scientific law is a rule of nature that sums up related observation s to describe a pattern in nature. A scientific theory is an explanation based on many observations supported by experimental results.
ON TARGET A theory is the best available explanation of why things work as they do. Laws and theories may be revised or discarded over time. Theories are changed and modified as new experiments provide insight and new observations are made.
ON TARGET MEASUREMENTS IN PHYSICS
ON TARGET MATHEMATICS AND PHYSICS Physics uses mathematics as a powerful language. In Physics, equations are important tools for modeling observations and for making predictions.
ON TARGET UNITS, STANDARDS AND THE SI SYSTEM The base units that will be used in this course are: meter, kilogram, second
ON TARGET All physical quantities are expressed in terms of base units. For example, the velocity is usually given in units of m/s. All other units are derived units and may be expressed as a combination of base units. For example: A Newton is a unit of force: 1 N = 1 kg.m/s 2
ON TARGET SYSTEME INTERNATIONAL The scientific community follows the SI Systeme International, based on the metric system: QuantityUnitSI symbol Lengthmeterm Masskilogramkg Timeseconds Electric currentampereA Thermodynamic temperature KelvinK Amount of substancemolemol Luminous intensitycandelacd
ON TARGET TYPES OF ERROR
ON TARGET There are two kinds of errors: systematic error and random error. A systematic error is constant throughout a set of measurements. The results will be either always larger or always smaller than the exact reading.
ON TARGET A random error is not constant. Unlike a systematic error, a random error can usually be detected by repeating the measurements.
ON TARGET PRECISION VS ACCURACY
ON TARGET Precision vs. Accuracy Accuracy - describes the nearness of a measurement to the standard or true value, i.e., a highly accurate measuring device will provide measurements very close to the standard, true or known values Precision is the degree to which several measurements provide answers very close to each other. It is an indicator of the scatter in the data. The lesser the scatter, higher the precision.
ON TARGET Not Precise, Not Accurate This is a randomlike pattern, neither precise nor accurate. The darts are not clustered together and are not near the bull's eye.
ON TARGET Accurate This is an accurate pattern, but not precise. The darts are not clustered, but their 'average' position is the center of the bull's eye.
ON TARGET Precise This is a precise pattern, but not accurate. The darts are clustered together but did not hit the intended mark.
ON TARGET Precise & Accurate This pattern is both precise and accurate. The darts are tightly clustered and their average position is the center of the bull's eye.
ON TARGET ORDER OF OPERATIONS Equations are used throughout the study of physics. These equations consist of operations such as addition, subtraction, multiplication, division, and trigonometric functions. When solving equations, it is important to follow an order in which the operations are performed. For example, what number is equal to x 2 - 5?
ON TARGET Order of Operations: 1. Perform all operations within grouping symbols, such as parentheses. 2. Evaluate all exponential expressions. 3. Evaluate all trigonometric functions. 4. Perform all multiplication and division in the order they occur from left to right. 5. Perform all addition and subtraction in the order they occur from left to right. PLEASE EXTERMINATE MY DEAR AUNT SALLY