Physics and Physical Measurement The Realm of physics Measurement and uncertainties.

Slides:

Advertisements

Similar presentations

Chapter 1 Chemistry and You

Advertisements

Uncertainty & Errors in Measurement. Waterfall by M.C. Escher.

All measurements have some degree of uncertainty

Introduction to experimental errors

Significant figures or Significant digits

Ch. 3.1 – Measurements and Their Uncertainty

Topic 11: Measurement and Data Processing

Errors and Uncertainties © Christopher Talbot and Cesar Reyes 2008

Reliability of Measurements

IB Chemistry Chapter 11, Measurement & Data Processing Mr. Pruett

1.2 Measurements and Uncertainties

Uncertainty in Measurement Professor Bob Kaplan University Department of Science 1.

Topic 11: Measurement and Data Processing

The ± 1 second is called the absolute uncertainty Every measurement has an uncertainty or error. e.g. time = 5 seconds ± 1 second There are three main.

MeasurementsandCalculations. Numbers Numbers in science are different than in math. Numbers in science always refer to something grams 12 eggs.

Accuracy: The closeness of a measurement to the true or actual value

Uncertainty and error Distinguish between precision and accuracy Accuracy is how close to the “correct” value Precision is being able to.

IB Physics Topic 1 Measurement and Uncertainties

Precision, Error and Accuracy Physics 12 Adv. Measurement  When taking measurements, it is important to note that no measurement can be taken exactly.

Accuracy and Precision

Scientific Methods Error Analysis Random and Systematic Errors Precision and Accuracy.

Unit 1- Units and Measurement Chemistry. Scientific Notation, Measurement, Accuracy, Precision, Error.

Honors Chemistry I. Uncertainty in Measurement A digit that must be estimated is called uncertain. A measurement always has some degree of uncertainty.

Calibration vs. Precision If a balance is accurate, it should read 0 when nothing is on it. The process for making sure a balance or any equipment is accurate.

Physics 11: Skills Review Significant Digits (and measuring, scientific notation, conversions……)

Uncertainties for AH Phys. Accuracy and Precision The accuracy of a measurement tells you how close the measurement is to the “true” or accepted value.

Uncertainty and Error in Measurement (IB text - Ch 11) (If reviewing this slide in the senior year, there is also uncertainty information in the AP text.

1© Manhattan Press (H.K.) Ltd. Measurements and errors Precision and accuracy Significant figures cientific notation S cientific notation Measurements.

Uncertainty in Measurement

Significant Figures A tutorial adapted from

Significant Figures When using calculators we must determine the correct answer. Calculators are ignorant boxes of switches and don’t know the correct.

Hwk Ans Key. Experimental Errors & Uncertainty.

Significant Figures A tutorial adapted from

1.3 Converting units  To convert 1,565 pennies to the dollar amount, you divide 1,565 by 100 (since there are 100 pennies in a dollar).  Converting SI.

Warm-up: Are these “errors”? 1. Misreading the scale on a triple-beam balance 2. Incorrectly transferring data from your rough data table to the final,

Uncertainty & Errors in Measurement. Waterfall by M.C. Escher.

Chapter 2 Measurements and Calculations Or It all adds up!

I. Types of Errors: Systematic Random

The significant figures in a measurement Consist of all the digits known with certainty plus one final digit, which is uncertain or is estimated. What.

Data Analysis Applying Mathematical Concepts to Chemistry.

Measurement and Data Processing Topic 11.1 & 11.2 (not 11.3)

Uncertainty and Significant Figures Cartoon courtesy of Lab-initio.com.

SPH3UIB 1 ST DAY NOTES Significant digits, Uncertainties, Error Calculations.

Accuracy & Precision & Significant Digits. Accuracy & Precision What’s difference? Accuracy – The closeness of the average of a set of measurements to.

Chemistry Chapter 2D Uncertainty in Measurement. Uncertainty  Represents how well a measurement was made  Science is ‘peer reviewed’  We don’t just.

CHEMISTRY CHAPTER 2, SECTION 3. USING SCIENTIFIC MEASUREMENTS Accuracy and Precision Accuracy refers to the closeness of measurements to the correct or.

Section 2.3. Accuracy: the closeness of measurements to the correct or accepted value of the quantity measured Precision: the closeness of a set of measurements.

 An understanding of uncertainty is an important pre-requisite for students in an introductory physics course to fully comprehend scientific measurement.

Precision, Error and Accuracy Physics 12. Measurement  When taking measurements, it is important to note that no measurement can be taken exactly  Therefore,

CHAPTER 3: MEASUREMENT. ACCURACY AND PRECISION Can never be exact Instrument marking can’t be fine enough Defective instrument Environmental conditions.

Uncertainty2 Types of Uncertainties Random Uncertainties: result from the randomness of measuring instruments. They can be dealt with by making repeated.

Ms. D CHEMISTRY Determining Significant Figures. Uncertainty in Measurement A digit that must be estimated is called uncertain. A measurement always has.

Measurements and their Uncertainty

Chapter 11: Measurement and data processing Objectives: 11.1 Uncertainty and error in measurement 11.2 Uncertainties in calculated results 11.3 Graphical.

Uncertainty in Measurement How would you measure 9 ml most precisely? What is the volume being measured here? What is the uncertainty measurement? For.

Uncertainty and Error in Measurement. Let’s Think… You measure the temperature of a glass of water 10 times, using 10 different thermometers. Results.

STUDY GUIDE: Page 11 - Q7 Page 12 - Q , 15 TEXT BOOK:

Topic 11 Measurement and data processing

Physics and Physical Measurement

Uncertainty in Measurement

Chapter 11 Notes Chapter 11.1 All measurement has a limit of precision and accuracy, and this must be taken into account when evaluating experimental results.

Errors and Uncertainties

Errors and Uncertainties

Uncertainty and Significant Figures

Topic 11: Measurement and Data Processing

UNIT 3 MEASUREMENT AND DATA PROCESSING

Uncertainty and Significant Figures

Measurements and Calculations.

Uncertainty and Significant Figures

Presentation transcript:

Physics and Physical Measurement The Realm of physics Measurement and uncertainties

Extra Book Physics: for use with the IB Diploma Program By Michael J Dickinson ISBN:

HertzHzfrequencys -1 CoulombCElectric charge As OhmΩelectrical resistance kg m 2 s -3 A -2 TeslaTmagnetic fluxWb m -2 WeberWbmagnetic flux(T m 2 ) or kg m -2 s -2 A Becquerel Bqradioactivitys -1

Uncertainty and Error There are two types of errors: Random and systematic Random errors can be reduced by repeating measurement many times. Systematic errors can be reduced by repeating measurement using a different method or different apparatus and comparing the results.

Sources of random errors the readability of the instrument the observer being less than perfect the effects of a change in the surroundings.

Sources of systematic errors an instrument with zero error an instrument being wrongly calibrated the observer being less than perfect in the same way every measurement.

Accuracy and precision Accuracy is how close to the “correct” value Precision is being able to repeatedly get the same value Measurements are accurate if the systematic error is small Measurements are precise if the random error is small.

Three Basic Rules Non-zero digits are always significant has ____ significant figures Any zeros between two significant digits are significant has ____ significant figures A final zero or trailing zeros if it has a decimal, ONLY, are significant has ____ significant figures 200 has ____ significant figures

Uncertainties All measurement involves readability error. If we use a graduated cylinder to find the volume of a liquid, the best estimate is 73cm 3, but we know that it is not exactly this value( cm 3 ). Uncertainty range is ± 5cm 3. We say volume = 73± 5cm 3.

Uncertainties in Calculations Random errors can be taken into account by use of an uncertainty range. An analogue scale is +/-half of the limit of reading. – Rulers, scales with moving pointers. A digital scale is +/-the limit of reading. – Ex. Top-pan balances, Digital meters

Uncertainties Examples InstrumentLimit of readingUncertainty Range Meter rule1mm+/- 0.5mm Vernier gauge0.1mm+/- 0.05mm Digital balance0.01g+/- 0.01g Digital stopwatch0.01s+/- 0.01s

We can express this uncertainty in one of three ways- using absolute, fractional, or percentage uncertainties – Absolute uncertainties are constants associated with a particular measuring device. – (Ratio) Fractional uncertainty = absolute uncertainty measurement – Percentage uncertainties = fractional x 100%

Example A meter rule measures a block of wood 28mm long. Absolute = 28mm +/- 0.5mm Fractional = 0.5mm = 28mm +/ mm Percentage = x 100% = 28mm +/- 1.79%

Graphs error bars. Since error bars represents the uncertainty range, the ‘best-fit’ line of the graph should pass through all of the rectangles created by the error bars. The best fit line is included by all error bars in the first two graphs. This is not true of the last graph. Systematic and random errors can often be recognized from a graph of the results.