Transcript Tools Measurements And Safety

Why is it important that we all
use the same system of measure
Tools & Measurements
S
Tools in Science
It is necessary to collect data in science, we do this by
taking measurements
It is important that you use the proper tools for your
situation
Some tools you might use are thermometers, stopwatches,
meter sticks and balances
After you collect data you must analyze it using a
calculator or a computer
Making Measurements
In the past many countries used different systems of
measure.
This caused problems when different countries were
trading
In the late 1700’s the French Academy of Science tried to
make a simpler system
Over 200 years the metric system was formed
Length
A meter is the basic si unit for length
Mass
Mass measures the amount of a matter in an object
The basic unit of mass is the kilogram
However the kilogram is used to measure large objects,
for smaller units you would use the gram
Volume
Volume is the amount of space that something takes up
Liquid volume is measured using liters, it is the most
commonly used unit of liquid volume
The volume of a solid object is expressed in cubic meters,
one cubic meter is equivalent to 1000 liters
Density
Density is the amount of matter in a given volume.
It is impossible to measure density directly, you must first
looks at the mass and volume
The equation for Density is D=m/V
Because we cannot determine it directly we call it a
derived quality
Density Continued
If you are measuring the density of an irregular object;
anything not rectangular, spherical, or triangular, you
have to see how much water the object displaces.
This is called Archimedes Principal, discovered by a
Greek Scientist
https://www.youtube.com/watch?v=ijj58xD5fDI
Temperature
Temperature is a measure of how hot a substance is
There are three measures of temperature Fahrenheit,
Celsius, and Kelvin
In Fahrenheit water freezes at 32 degrees and boils at 212
In Celsius water freezes at 0 degrees and boils at 100
degrees
In the Kelvin system water freezes at 273.15 and boils at
373.15
Density Practice
A piece of wood has a mass of 35
grams. If its volume is 7 cm3, What is
its density?
Density Practice
The density of a substance is
3
7.8 g/cm . What volume does
39 grams of it take up?
Density Practice
The density of water is 1
g/ml. What mass does 30 ml of
water have?
Density Practice
What is the volume of a tank that
can hold 18,754 Kg of methanol
whose density is 0.788g/cm3?
Density Practice
Calculate the mass of a liquid with a
density of 3.2 g/mL and a volume of 25
mL.
Density Practice
An irregular object with a mass of 18 kg
displaces 2.5 L of water when placed in a
large overflow container. Calculate the
density of the object.