Wild Williams's Physical Science Lab

Units are known amounts used for measuring. If I say I have
22. No one would understand what I had (22 what?).
It could be donkeys, boogers, dates this weekend or anything.
I have to tell what I am talking about. This is where the unit
comes into play. Units give meaning to the numbers. They
are extemely important . A good example is the above
statement. I have 22. I may have 22 dollars or 22 cents.
Does it matter? Is it important? Oh yeah!!

Down through the ages mankind has established standards
that most everyone in society can understand. We use them
in comparison with all the things that we need to measure.
In the English System, a system of measurement that uses inches,
feet, and yards, once the size of the king's foot was
just such a standard. Thus we get the unit, foot. Scientist
and most people in the world use the SI or Metric System
for their measuements. The chart below contains some of
the base Units and their uses that will be very important in
this class.


Measurement	Tool	Definition	Metric Unit for Measuring Property	English Unit for Measuring Property
Length	Metter Stick	a measured distance or dimension	Meter	Foot
Mass	Balance Scales	a measure of how much matter is in an object	Gram	Pound
Weight	Spring Scale	A measure of the force of gravity on an object	Newtons	Pound
Volume Length x Width x Height Displacement	Graduated Cylinder Meter Stick	The amount of space that matter occupies	Cubic Centimeter Liter	Ounces
Density Mass/Volume	Balance Scales Graduated Cylinder	The measurement of how much mass of a substance is in a certain volume	Grams/Cubic Centimeters	Pounds/Cubic Foot
Force Mass x Acceleration	Spring Scale Watch	The push or pull on an object	Newton	Pound-Force
Work Force x Distance	Spring Scale Meter stick	The product of force and distance when force is used to move an object	Joule Newton Meter	Foot pound-Force
Power work/time	Spring Scale Meter stick Watch	Rate of doing work or the rate at which one form of energy is converted to another	Watt One joule per second	Foot pound -force per second horsepower
Heat Energy	Calorimeter	The movement of thermal energy from one substance to another-results from the movement of particles in matter-flows from hot to cold	Joule, Calorie, 1 Cal = 4186 joules	British Thermal Unit
Temperature	Themometer	The measure of the average kinetic energy of the particles of a substance-how fast the particles are moving	Degrees Kelvin	Degrees Fahrenheit
Voltage	Volt meter	The difference in electrical potential between two places-The energy (force /push) that a powersource gives to electrons in a circuit	Volt	None
Electric Current	Amp meter	Movement of electrons from one place to another orThe flow of electric charges through a material (how many electron)	ampere	None
Electrical Resistance (volt / ampere)	Ohm meter	The measure of hoe easily electric current will flow through a material	Ohm	.
Electric Power Volts x Amps	Volt meter Amp meter	The amount of electrical energy used ina given time	Watt	None
Magnetic Field Intensity	.	.	oersted	none

The Metric System also is cleverly designed so that the
number of units that one has to know is small and changing
between or converting between units is easy. The system uses prefixes
or letters that can be added to the beginning of a word. Just like in
the word submarine. sub is a prefix that means below. Marine means
having to do with the ocean. So sub marine means below the ocean.
The following chart is a list of metric prefixes and their meaning.
These can be added to the beginning of all words charted above.


Prefix	Symbol	Numerical Multiplier	Exponential Multiplier 10
Giga	G	1,000,000,000	9
Mega	M	1,000,000	6
Kilo	k	1000	3
Hecto	h	100	2
Deca	da	10	1
Base unit		1	0
Deci	d	.1	-1
Centi	c	.01	-2
Milli	m	.001	-3
Micro	m	.000001	-6
Nano	n	.000000001	-9

If I had 1 gigadollar I would have $1,000,000,000 and we would have an even more amazing time in class. But recieved 1 nanodollar a day I would have to save up 10,000,000 days to buy a penny candy.

Converting Between Metric Units by Moving the Decimal

When converting 8 kilometers to decimeters, otherwise stated “How many decimeters are in 8 kilometers?” The understood decimal to the right of the 8 is moved 4 places on the chart (to the “deci” place. Zeros fill in each moved place. The answer is 80,000 centimeters are in 8 kilometers.

To convert 5000 millimeters to dekameters move the decimal and count the spaces between milli and deka . Then move the understood decimal at the right of the 5000 the appropriate 4 places. The answer is .5000 or .5