Tools, Meas, Safety Ch1.4 8th

TOOLS, MEASUREMENT, AND SAFETY Chapter 1 Section 4

OBJECTIVES 

Identify tools used to collect and analyze data



Explain the importance of the International System of Units



Identify the appropriate units to use for particular measurements

TOOLS IN SCIENCE 

Used to take measurements and analyze data

Stopwatches  Meter sticks  Balances  Thermometers  Calculators  Computers 

MAKING MEASUREMENTS 

The International System of Units  Metric

system was formed and developed over the last 200 years

 Called

SI units

 Expressed  Basic

in multiples of 10

units: meter, gram

 Prefixes

are used (ex: kilo-, milli-)

LENGTH 

Basic SI unit: meter

1km = 1,000m  1dm = 0.1m  1cm = 0.01m  1mm = 0.001m  1μm = 0.000001m  1nm = 0.000000001m 

MASS 

The amount of matter in an object



Basic unit for mass: kilogram (kg)



1kg = 1,000g



Very large objects are measured in metric tons (=1,000kg)

VOLUME 

The amount of space that something occupies



The measure of the size of an object or region in 3-D space



Liquid volume is measured in liters (L)



Liters are based on the meter; a cubic meter (1m³) = 1,000 L



1mL = 1 cm³

VOLUME OF A RECTANGULAR SHAPE 

Multiply length x width x height

DENSITY 

If you know the mass and the volume of an object, you can determine density.



Definition: the amount of matter in a given volume



Formula: D = M/V



Derived quantity: it is found by combining 2 basic quantities (mass & volume)

TEMPERATURE 

A measure of how hot or cold something is



A measure of the average kinetic energy of the particles in an object



Degrees Fahrenheit (Fº) or Celsius (Cº)



SI units of temperature: Kelvin (K) *(degree sign is not used for Kelvin)

TEMPERATURE COMPARISONS 

212ºF and 100ºC - water boils



98.6ºF and 37ºC - normal body temperature



32ºF and 0ºC - water freezes

QUICK QUIZ



What does SI stand for?



What is the SI unit for length?