# Sig figs. Rounding rules Scientific notation

## Sig figs. Rounding rules Scientific notation

Maggio, Jason, Founder has reference to this Academic Journal, PHwiki organized this Journal Chapter 1 INTRODUCTION The Science of Physics Section 1 What is Physics Chapter 1 The Topics of Physics Physics is simply the study of the physical world. Your goal in Physics is to use a small number of basic concepts, equations, in addition to assumptions to describe the physical world. This will allow you to make predictions about a broad range of phenomena. Section 1 What is Physics Chapter 1 The areas of Physics 1. Mechanics – The study of motion in addition to its causes. Falling objects, friction, weight, spinning objects. 2. Thermodynamics  The study of heat in addition to temperature. Melting in addition to Freezing processes, engines, refrigerators. 3. Vibration in addition to Wave Phenomena  The study of specific types of repetitive motion. Springs, pendulums, sound

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Section 1 What is Physics Chapter 1 The areas of Physics (cont) 4. Optics  The study of light. Mirrors, lenses, color, astronomy 5. Electromagnetism  The study of electricity, magnetism, in addition to light. Electrical charge, circuitry, permanent magnets, electromagnets. 6. Relativity  The study of particles moving at any speed, including very high speed. Particle collisions, particle accelerators, nuclear energy. Section 1 What is Physics Chapter 1 The areas of Physics (cont.) 7. Quantum Mechanics  The study of submicroscopic particles. The atom in addition to its parts Types of observations Qualitative- descriptive, but not true measurements Hot Large Quantitative- describe with numbers in addition to units 100C 15 meters Chapter 1

Section 1 What is Physics Chapter 1 The Scientific Method The scientific method is a way to ask in addition to answer scientific questions by making observations in addition to doing experiments. Steps of the scientific : Observation (Ask a Question) Collect Data (Do Background Research) Construct a Hypothesis (Educated guess) Test Your Hypothesis by Doing Experiments Analyze Your Data in addition to Draw a Conclusion The conclusion is only valid if it can be verified by other people. Communicate Your Results Chapter 1 The Scientific Method Section 1 What is Physics Section 1 What is Physics Chapter 1 The Scientific Method (cont) System  A set of items or interactions considered a distinct physical entity as long as the purpose of study. Decide what to study in addition to eliminate everything else that has minimal or no effect on the problem. Draw a diagram of what remains (Model) Models  A replica or description designed to show the structure or workings of an object, system, or concept. Models help guide experimental design

Chapter 1 The System Section 1 What is Physics Chapter 1 The Scientific Model Section 1 What is Physics Section 1 What is Physics Chapter 1 The Scientific Method (cont) Hypothesis  A reasonable explanation as long as observations, one that can be tested with additional experiments. The hypothesis must be tested in a controlled experiment. Controlled Experiment- Only one variable at a time is changed to determine what influences the phenomenon you are observing.

Section 2 Measurements in Experiments Chapter 1 Numbers As Measurements Numerical measurements in science contain the value (number) in addition to Dimension. Dimension is the physical quantity being measured (length, mass, time, temperature, electric current) Each dimension is measured using units in addition to prefixes from the SI system. The dimension must match the unit. (ex. If you are measuring length, use the meter(m), not the kilogram(kg) Section 2 Measurements in Experiments Chapter 1 SI is the st in addition to ard measurement system as long as science. Used so that scientists can communicate with the same language. There are seven base units. They are: Meter(m)  length kilogram(kg)  Mass Second(s)  Time Kelvin(K)  Temperature Ampere(A)  current Mole(mol)  amount of substance C in addition to ela(cd)  luminous intensity How good are the measurements Scientists use two word to describe how good the measurements are: Accuracy- how close the measurement is to the actual value. Precision- how well can the measurement be repeated.

Differences Accuracy can be true of an individual measurement or the average of several. Problems with accuracy are due to error Precision requires several measurements be as long as e anything can be said about it. Precision describes the limitation of the measuring instrument. Percent Error Percent error = (Experimental Value  Accepted value) x 100 Accepted Value Percent error can be negative. Percent Error Absolute value of error I know that I weigh 150 kg. If I weigh myself in addition to the balance says 165 kg, what is the percent error

Significant Figures Pacific Atlantic Present Absent If the decimal point is absent, start at the Atlantic (right), find the first non zero, in addition to count all the rest of the digits 230000 1750 Pacific Atlantic Present Absent If the decimal point is PRESENT, start at the Pacific (left), find the first non zero, in addition to count all the rest of the digits 0.045 1.2300

Sig figs. How many sig figs in the following measurements 458 g 4085 g 4850 g 0.0485 g 0.004085 g 40.004085 g 405.0 g 4050 g 0.450 g 4050.05 g 0.0500060 g Rounding rules Look at the number behind the one youre rounding. If it is 0 to 4 dont change it. If it is 5 to 9 make it one bigger. Round 45.462 to four sig figs= to three sig figs. to two sig figs. to one sig figs. 45.46 45.5 46. 50 Scientific notation All non-zero digits in scientific notation are significant figures. Any ending zero will be after the decimal point to be significant 1.20 x 103 Sometimes you must write in scientific notation to use the correct sig figs.

Adding in addition to subtracting with sig figs have to round it to the least place of the measurement in the problem. For example First line up the decimal places Then do the adding 34.33 Find the estimated numbers in the problem. This answer must be rounded to the tenths place. Practice 4.8 + 6.8765 520 + 94.98 0.0045 + 2.113 500 -126 6.0 x 103 – 3.8 x 102 6.0 x 10-2 – 3.8 x 10-3 5.33 x 1022 – 3.8 x 1021

A barrel of petroleum holds 42.0 gal. Empty it weighs 75 lbs. When it is filled with ethanol it weighs 373 lbs. What is the density of ethanol in g/cm3 1 qt = 2 pints 1 yd = 3 ft. 1 mile = 1.61 km 1 m = 1.094 yds 1 L = 1000 cm3 1 gal = 4 qt 1 L = 1.06 qt 1 lb = 454 g 1 mi =1760 yds 1 pint = 2 cups

## Maggio, Jason Founder

Maggio, Jason is from United States and they belong to Vapors Magazine and they are from  Los Angeles, United States got related to this Particular Journal. and Maggio, Jason deal with the subjects like Popular Culture

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