Measurement

Stretch your mind: You are given a bottle of water and 3 beakers. One of the beakers holds 30mL, one holds 40mL, and the largest of the three beakers holds 200mL when full. There are no markings on any of the beakers. How can you put 20mL of water in the largest beaker without using any other equipment?

Tools of the Trade What measuring instrument can be used to determine the following? how much cloth a tailor needs for a pair of pants how long you should boil the egg whether or not you have a fever how much cough syrup you should take how much flour should be added to the batter

7 Base (Fundamental) Quantities Base QuantitySI Unit lengthmeter (m) masskilogram (kg) timesecond (s) electric currentampere (A) temperaturekelvin (K) amount of substancemole (mol) luminous intensitycandela (cd) * The base quantities are assumed to be mutually independent. Take from NIST website

Some Derived Quantities Derived Quantity SI Derived Unit area square meter (m 2 ) volume cubic meter (m 3 ) density kilogram per cubic meter (kg/m 3 ) speed, velocity meter per second (m/s) acceleration meter per second squared (m/s 2 ) force, weight kilogram meter per second squared (kg ⋅ m/s 2 ) or newton (N) energy newton meter (N ⋅ m) or joule (J) Take from NIST website

Tools of the Trade

Metric Prefixes Take from NIST website The METRIC SYSTEM

Precision and Accuracy What is precision? What is accuracy? How do we obtain precise and accurate measurements?

Writing Measurements number +unit In every measurement, there should be a... Precision of instrument = smallest calibration or finest division In writing measurements, always include the estimated digit! how much there is of somethingstandard we are comparing the value to

Let’s Practice! Give the measurement reading:

Let’s Practice! Give the measurement reading:

Let’s Practice! Give the measurement reading:

Let’s Practice! Give the measurement reading:

Let’s Practice! Give the measurement reading: in degree Celsius