Summary of Standard Measurements Physical Science Summary of Standard Measurements

Standard Measurements Scientific experiments Exact quantity that people agree for comparison Measurements are made using same standard Compared to each other SI Base unit (length, time, mass, temperature, and volume, density) Powers of 10

SI units Length (m) Conversions can be done by multiplying or dividing units by powers of 10 (10, 100, 1000) Number and unit label Larger to smaller (multiply or move decimal right) Smaller to larger (divide or move decimal left) Prefixes remain the same not matter what base unit Mili-, centi- K h da base unit d c m _ _ _ (L, m, g) 532cm to meters?

SI units K h da base unit d c m _ _ _ 532cm to meters? 53200m (L, m, g) 532cm to meters? 53200m

ACCURACY VS PRECISION Accuracy Precision Relates to closeness of a measured value to a standard or known value How correct a measurement is Precision How repeatable a measurement is You can be precise but not accurate Significant digits in calculations

Volume Space occupied by an object cm3 (know 1cm3 = 1mL) Length X Width X Height

Mass and Density Mass Density Matter of an object kg or g Density Derived unit since you find density by combining units from mass and volume Mass divided by volume (g/cm3)

Time and Temperature Time (s) Temperature Celsius (C ) scale 00 water freezes 1000 water boils SI unit Kelvin (K) add 273 to Celsius value

Graphing Visual display of information Correct graph for data displayed Line graphs Show trends or data (change over time) Independent variable (x – axis) time Dependent variable (y – axis) temperature Bar graph Comparing information collected by counting Circle graph Show how fixed quantity is broken down into parts, %