Measurement and Physical Quantities.pptx

Assignment 1 Research and Print the Metric Conversion Table or Chart (1 whole yellow pad) Research and Explain/Define 1. Length 4. Electric Current 2. Mass 5. Temperature 3. Time 6. Amount of Substance Provide 1 example for each quantity demonstrat...

Assignment 1 Research and Print the Metric Conversion Table or Chart (1 whole yellow pad) Research and Explain/Define 1. Length 4. Electric Current 2. Mass 5. Temperature 3. Time 6. Amount of Substance Provide 1 example for each quantity demonstrating how it is measured in real-world scenarios. MEASUREMEN Learning Objectives Solve measurement problems involving conversion of units, expression of measurement and scientific notation.  Measurement in everyday life Measurement of mass Measurement of volume  Measurement in everyday life Measurement of length Measurement of temperature  Need for measurement in physics To understand any phenomenon in physics we have to perform experiments. Experiments require measurements, and we measure several physical properties like length, mass, time, temperature, pressure etc. Experimental verification of laws & theories also needs measurement of physical properties.  Physical Quantity A physical property that can be measured and described by a number is called physical quantity. Examples: Mass of a person is 65 k g. Length of a table is 3 m. Area of a hall is 100 m2. Temperature of a room is 300 K  Types of physical quantities 1. Fundamental quantities: The physical quantities which do not depend on any other physical quantities for their measurements are known as fundamental quantities. Examples: Mass Time Length Temperature  Types of physical quantities 2. Derived quantities: The physical quantities which depend on one or more fundamental quantities for their measurements are known as derived quantities. Examples: Area Speed Volume Force  Units for measurement The standard used for the measurement of a physical quantity is called a unit. Examples: metre, foot, inch for length kilogram, pound for mass second, minute, hour for time fahrenheit, kelvin for temperature Characteristics of units Well – defined Suitable size Reproducible Invariable Indestructible Internationally acceptable  CGS system of units This system was first introduced in France. It is also known as Gaussian system of units. It is based on centimeter, gram and second as the fundamental units of length, mass and time.  MK S system of units This system was also introduced in France. It is also known as French system of units. It is based on meter, kilogram and second as the fundamental units of length, mass and time.  FPS system of units This system was introduced in Britain. It is also known as British system of units. It is based on foot, pound and second as the fundamental units of length, mass and time.  International System of units (SI) In 1971, General Conference on Weight and Measures held its meeting and decided a system of units for international usage. This system is called international system of units and abbreviated as SI from its French name. The SI unit consists of seven fundamental units and two supplementary units.  Seven fundamental units FUNDAMENTAL QUANTITY SI UNIT SYMBOL Length metre m Mass kilogram kg Time second s Temperature kelvin K Electric current ampere A Luminous intensity candela cd Amount of substance mole mol  Rules for writing SI units 1 Full name of unit always starts with small letter even if named after a person. newton Newton ampere not Ampere coulomb Coulomb  Rules for writing SI units 2 Symbol for unit named after a scientist should be in capital letter. N for newton A for ampere K for kelvin C for coulomb  Rules for writing SI units 3 Symbols for all other units are written in small letters. m for meter k g for kilogram s for second cd for candela  Rules for writing SI units 4 One space is left between the last digit of numeral and the symbol of a unit. 10 k g 10k g 5N not 5N 15 m 15m  Rules for writing SI units 5 The units do not have plural forms. 6 metre 6 ms 14 k g 14 k gs not 20 second 20 ss 18 kelvin 18 ks  Rules for writing SI units 6 No space is used between the symbols for units. 4 J/s 4Js 19 Nm not 19 N m. 25 VA 25 V A.  SI prefixes Factor Name Symbol Factor Name Symbol yotta Y deci d zetta Z centi c exa E milli m peta P micro μ tera T nano n giga G pico p mega M femto f kilo k atto a hecto h zepto z deka da yocto y  Use of SI prefixes 3 milliampere = 3 mA = 3 x A 5 microvolt = 5 μV = 5 x V 8 nanosecond = 8 ns = 8 x s 6 picometre = 6 pm = 6 x m 5 kilometre = 5 km = 5 x m 7 megawatt = 7 MW = 7 x W  Some practical units for measuring length 1 micron = m 1 nanometer = m Bacterias Molecules  Some practical units for measuring length Astronomical unit = It is defined as the mean distance of the earth from the sun. 1 astronomical unit = m Distance of planets  Some practical units for measuring length Light year = It is the distance travelled by light in vacuum in one year. 1 light year = m Distance of stars  Some practical units for measuring time 1 Solar day = 24 h 1 Sidereal day = 23 h & 56 min 1 Solar year = 365 solar day = 366 sidereal day 1 Lunar month = 27.3 Solar day 1 shake = s  EXAMPLES 1. How many inches are there in 10 meters? 2. The speed of a car as measured by a speedometer is 62 km/h, convert this unit to cm/s 3. How many yards are there in 1km?  Seatwork 1 1. 29. 18 k g = ______slug 2. 432 = ________ 3. 18.94 li = _______gallon 4. 264 ft/s = ________mi/hr 5. A man is 5’9 tall. What is his height in cm? Thank You