GEN PHY 1_UNITS & MEASUREMENTS, PHYSICAL QUANTITIES.pdf

SACRED HEART ACADEMY OF NOVALICHES GENERAL PHYSICS 1 Prepared by Mr. Joseph Roy E. Torion WHAT IS PHYSICS? WHAT IS ITS IMPORTANCE? What is Physics? Physics is how the universe works. Physics is devoted to the understanding of all natural phenomena. In physics, we try t...

SACRED HEART ACADEMY OF NOVALICHES GENERAL PHYSICS 1 Prepared by Mr. Joseph Roy E. Torion WHAT IS PHYSICS? WHAT IS ITS IMPORTANCE? What is Physics? Physics is how the universe works. Physics is devoted to the understanding of all natural phenomena. In physics, we try to understand physical phenomena at all scales—from the world of subatomic particles to the entire universe. Let’s play CHARADES! Map of Physics Map of Physics Map of Physics Map of Physics Map of Physics Map of Physics Map of Physics Map of Physics Map of Physics Map of Physics Map of Physics Map of Physics Map of Physics Map of Physics General Physics 1 Units and Measurements Prepared by Mr. Joseph Roy E. Torion Learning Competencies The learners should be able to differentiate accuracy from precision and random errors from systematic errors by solving/estimating physical quantities.  Learning Targets 1. Solve measurement 2. Differentiate problems involving accuracy from conversion of units, precision and random expression of errors from systematic measurements in errors scientific notation  Learning Targets 3. Use the least count 4. Estimate errors from concept to estimate multiple measurements errors associated with of a physical quantity single measurements using variance Learning Targets 5. Estimate the uncertainty of a derived quantity from the estimated values and uncertainties of directly measured quantities  Essential Question: How can we determine the reliability of measurements in different situations?  What is Physical Quantity? Physical Quantities Physics is one of the main branches of science which aims to gain greater understanding of the nature of matter and energy. Thus, it is involved with measurable quantities which describe a certain property of a material. These are known Physical Quantities. What is a Unit? UNIT UNIT UNIT UNIT UNIT  Why are Units important? Why are units important? Why are units important? Why are units important? SI Units Physical Quantities can be described using different units. For example, the length of an object can be described as in meters, inches, or in feet. Thus, the metric system or the International System of Units (SI) was devised to set standard units for different measurements. SI Units SI Units SI Units SI Units  How to convert between units? Unit Conversion Unit Conversion Unit Conversion Unit Conversion Unit Conversion Unit Conversion Unit Conversion Unit Conversion Unit Conversion Unit Conversion Unit Conversion Unit Conversion Unit Conversion Recap Recap Recap Prefixes & Scientific Notation The numbers we deal with in everyday life are pretty easy to write - 5 miles, 7 kilometers, $80, 20 cm, 10 minutes. In Physics, it is common to encounter problems involving large or small numbers. Thus, scientists developed a way to simplify such numbers into scientific notation. Prefixes & Scientific Notation In scientific notation, the zeroes are converted into an exponential form of base 10 raised to the number of zeroes.  How do we deal with writing really big or small numbers? Reall big and really small numbers Reall big and really small numbers Reall big and really small numbers Reall big and really small numbers Reall big and really small numbers Reall big and really small numbers Reall big and really small numbers Reall big and really small numbers Prefixes Prefixes Prefixes Prefixes Prefixes Prefixes Prefixes Prefixes Scientific Notation Scientific Notation Scientific Notation Scientific Notation Scientific Notation Scientific Notation Scientific Notation Scientific Notation Scientific Notation Scientific Notation Scientific Notation Scientific Notation Scientific Notation Scientific Notation Recap Recap Recap Assignment #1 Sample problem 1.1: Transform the following values into scientific notation: (a) 0.0001 (b) 1000 Sample problem 1.2: Apply the proper prefix for the following quantities: (a) 3 X 10^3 m (b) 6 X 10^-6 g In everyday life, we use the words PRECISE and ACCURATE interchangeably. In physics, do you think these two terms are interchangeable? Accuracy and Precision Accuracy is how close a measurement is to the accepted reference value for that measurement. The precision of measurements refers to how close the agreement is between repeated independent measurements (which are repeated under the same conditions). Differentiating accuracy and precision Differentiating accuracy and precision Differentiating accuracy and precision Differentiating accuracy and precision Differentiating accuracy and precision To verify the value of acceleration due to gravity (9.8 m/s^2), the grade 12 STEM students conducted an experiment. Here are the results of the experiment of one group. Are the results precise? Are the results accurate? Differentiating accuracy and precision Differentiating accuracy and precision Differentiating accuracy and precision Differentiating accuracy and precision Differentiating accuracy and precision Differentiating accuracy and precision Differentiating accuracy and precision Differentiating accuracy and precision Differentiating accuracy and precision Differentiating accuracy and precision What is an ERROR? Systematic and Random Error Systematic and random error are an inevitable part of measurement. Error is not an accident or mistake. It naturally results from the instruments we use, the way we use them, and factors outside our control. Systematic and Random Error Systematic error is consistent, reproducible error that is not determined by chance. Systematic error introduces inaccuracy into measurements, even though they may be precise. Systematic and Random Error Averaging repeated measurements does not reduce systematic error, but calibrating instruments helps. Systematic error always occurs and has the same value when repeating measurements the same way. Systematic and Random Error As its name suggests, random error is inconsistent error caused by chance differences that occur when taking repeated measurements. Random error reduces measurement precision, but measurements cluster around the true value. Systematic and Random Error Averaging measurements containing only random error gives an accurate, imprecise value. Random errors cannot be controlled and are not the same from one measurement to the next. Systematic and Random Error Recap  ACTIVITY: Accuracy vs. Precision Beanbag Toss ACTIVITY: Accuracy vs. Precision Beanbag Toss ACTIVITY: Accuracy vs. Precision Beanbag Toss ACTIVITY: Accuracy vs. Precision Beanbag Toss ACTIVITY: Accuracy vs. Precision Beanbag Toss ACTIVITY: Accuracy vs. Precision Beanbag Toss