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 TradeWhat 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) QuantitiesBase

QuantitySI Unit

length meter (m)mass kilogram (kg)time second (s)

electric current ampere (A)temperature kelvin (K)

amount of substance mole (mol)luminous intensity candela (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 (m2)

volume cubic meter (m3)

density kilogram per cubic meter (kg/m3)

speed, velocity meter per second (m/s)

acceleration meter per second squared (m/s2)

force, weightkilogram meter per second squared

(kg⋅m/s2)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 something standard 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