Units and Measurement. - ppt video online download

$ 7.99

4.7 (638) In stock

A) SI Units, Scientific Notation, Measurement, Accuracy, Precision, Error
SI Units – International System. MKS. Meter m. Mass kg. Time s. National Bureau of Standards. Prefixes.
10-1. centi- c milli- m micro- μ nano- n pico- p
10 is the base. n is the exponent or power of 10.
Other Examples: 5.45E x 10^6
A millionth of a second is: sec 1x E-6 1.0x10^-6.
Limits of Measurement Accuracy and Precision
Accuracy - a measure of how close a measurement is to the true value of the quantity being measured.
17.0cm, 16.0cm, 18.0cm, 15.0cm. Amy: 15.5cm, 15.0cm, 15.2cm, 15.3cm.
A measure of how exact a measurement is..
Not Precise. Not Accurate. Precise. Accurate. Precise.
Error Error= experimental –accepted value
Percent Error % Error= |experimental –accepted| x100 accepted value
Significant Figures The significant figures in a measurement include all of the digits that are known, plus one last digit that is estimated.
Centimeters and Millimeters
Graduated Cylinder - Meniscus
How many sig figs are there in a given measurement
When the decimal is absent, start counting from the right. Zeroes encountered before a non zero digit do not count.
The result has the same number of decimal places as the number in the operation with the least decimal places. Ex: 2.33 cm cm. 5.3 cm.
The answer has the same sig figs as the factor with the least sig figs. Ex: 3.22 cm. x 2.0 cm. 6.4 cm2.
Counting Numbers Counting numbers have infinite sig figs. Ex: 3 apples
C) International System of Units and Prefixes
K. Time. second. s. Amount of Substance. mole. mol. Luminous Intensity. candela. cd. Electric Current. ampere. a.
Quantity. unit. Symbol. Volume. cubic meter. m3. Density. kilograms per cubic meter. kg/m3. Speed. meter per second. m/s. Newton. kg m/ s2. N. Energy. Joule (kg m2/s2) J. Pressure. Pascal (kg/(ms2) Pa.
Units for Volume m3 cm3 dm3 L Liter mL 1 dm3 = 1L 1cm3= 1mL
SI Unit: the kelvin ( K ) Note: not a degree. Absolute Zero= 0 K.
Celsius and Kelvin K= oC + 273
Farenheit and Celsius oF= (1.8 oC ) +32
Unit for Weight 1 Newton 1 N= kg m/s2
1 cal = quantity of heat needed to raise the temp of 1g of water by 1 oC.
Note: 1 Cal = 1kcal =1000cal
Name. Symbol. Analogy. gigameter. Gm megameter. Mm kilometer. km decimeter. dm centimeter. cm millimeter. mm micrometer. μm nanometer. nm picometer. pm
D) Factor Label Method of Unit Conversion- Dimensional Analysis
5km x 1,000m =5,000m. km. OLD UNIT.
Convert 7,000m to km 7,000m x 1 km = 7 km 1,000m
Convert 2.45cs to s 2.45cs x 1 s = s 100cs