Mediciones Mr. Ferron – PSJA High School Dual Language Program
Disena una unidad de medicion En grupos, disena una unidad de medicion
Sistema Internacional de Unidades “Systeme International d’Unites” Usado en todo el mundo Se usa tambien en Estados Unidos, pero no tanto como en otros paises. Es el sistema mas usado en ciencias.
Masa El KILOGRAMO (Kg) es la unidad estandard de masa. Un Kg = 1000 gramos = 1 Litro de agua Las replicas del Kilogramo original son muy bien guardadas alrededor del mundo.
Calcula tu peso en libras y kilogramos Libras
Lenght The Meter is the SI unit of length.
Temperature 1 Kelvin = 1 Celsius Celsius = 1 ([Fahrenheit]-32)x (5/9) 0 Kelvin = Absolute Zero!! Room Temp = 298K
Quantity The mole is the SI Unit of a quantity of a substance Is represented by Avogadro’s number 6.022x10 number of things 23
Accuracy and Precision Accuracy is the degree of closeness between a recorded measurement and the accepted value. Precision is the degree of closeness between one measurement and the other.
Percent Error Percent error is the ratio used to indicate the accuracy of measurements made by a person. %E = [O-A] A x100
Which one is more precise? A B
Rules for Significant Figures 1. All non-zero digits are significant. Ex. Numbers 1,2,3,4,5,6,7,8,9 are all significant. 2. All captive zeros (zeros between two non-zero digits) are significant. Ex. 102 and 1.02 both have 3 sig figs. 3. All exact numbers have infinite sig figs. Ex. π has infinite figs ( ……..). 4. Leading zeros are never significant. Ex has only 2 sig figs 5. Trailing zeros are significant only if there is a decimal point in the number. Ex has 4 sig figs Ex2. 5,400 has only 2 sig figs Ex has no sig figs. A number made only of zeros has NO SIG FIGS
How many significant figures? Pi 3. 7,000, x x
Write the following in scientific notation ,000,000,000, ,000,000,346