2010 On Line Technocracy Study Course project
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In the previous lesson we dealt with the nature and structure of matter, and showed that all matter was composed of some combination of the 92 chemical elements...
Lesson 2
...It was also shown that
matter can be changed from one physical state to another, or from one chemical
combination to another, but that in any of these processes which occur
naturally on the earth matter is not destroyed. Page 23 Under
what circumstances does matter move? Before this can be answered a number of
important relationships involving movements of matter must be investigated. Units of
Measurements.
Measurements of
length and distance: Metric System: Relation between English
and Metric Units: The
metric system is used universally outside of English speaking countries, and is
in general use in all scientific work. Mass. Units of Mass. Metric System: Relation between English
and Metric units: Time. Force. Measurement of
Force. Metric System: Page
24 GO Top Lesson 2 Bottom
centimeter per second for
each second the force is applied. If a force of one dyne is applied to a gram
mass originally at rest it will begin to move and continually increase in
velocity. At the end of the first second it will have a velocity of one centimeter
per second; at the end of the next second its velocity will be two centimeters
per second, etc. If the one gram mass is already moving, and a force of one
dyne be applied so as to retard its motion, at the end of each second its
velocity will be one centimeter per second slower than at the end of the second
preceding. The
pull of gravity on a one gram mass is, at the latitude of New York, 981 dynes.
A nickel coin has a mass of about five grams. Thus one dyne is approximately
one 5000th part of the pull of gravity on a nickel. Relation between Dynes
and Pounds of Force: Work. Measurement of
Work. Metric System: Power. Measurement of
Power. Page 25 Metric System: GO Top Lesson 2 Links to lessons
(Part One)
English System:
12 inches equals 1 foot; 3 feet equals one
yard.
100 centimeters equals 1 meter.
2.54 centimeters equals 1 inch.
Mass is that property of matter which is
most commonly manifested as weight. Weight, however, is due to the attraction
of the earth upon a massive body. Imagine two footballs suspended in space with
no gravitational attraction. Suppose one of them was filled with air and the
other with lead. Neither would weigh anything, but if a person were given the
privilege of kicking one of them he would choose the one with air, otherwise if
he kicked the one with the lead he would break his foot. Thus that property of
matter that causes it to tend to resist a change of motion is said to be its
mass.
English System:
16 avoirdupois ounces equals I pound; 2,000
pounds equals 1 short ton.
1,000 grams equals 1 kilogram.
1 pound equals 453.59 grams.
The unit of time is the second. One second
equals one 86400th part of a mean solar day; 60 seconds equals one minute; 60
minutes equals one hour; 24 hours equals one mean solar day.
Any body at rest or in motion will continue
at rest or in the same state of motion unless acted upon by an outside force.
Therefore, force is anything that tends to change the state of motion of
a mass whether at rest or already in motion. Examples: Pull of stretched coil spring or rubber
band, tension on a taut rope, push on the piston of a steam engine,
gravitational attraction of earth on a mass, attraction of magnet on iron.
English System:
A force of one pound is the force the
earth's gravitational attraction exerts on a mass of one pound.
The metric unit of force is the dyne.
If a force of one dyne is applied to a freely moving mass of one gram the
velocity of this gram mass will be changed by an amount of one
454 grams mass equals I pound mass. The
pull of gravity on 1 gram mass equals 981 dynes. The pull of gravity on 454
grams of mass equals 454 x 981, equals 445,374. Therefore, I pound of force
equals approximately 445,500 dynes.
When a force acts on a body in such a
manner as to cause it to move, this force is said to do work on the
body. The amount of work done is dependent upon both the magnitude of the force
and the distance the body is made to move. Thus the work done is the product of
the force applied in the direction of motion and the distance moved.
English System:
When a force of one pound moves a body a
distance of one foot in the direction of the force the work done is one foot-pound.
This is true whether the direction is horizontal or vertical.
When a force of one dyne moves a body a
distance of one centimeter the work done is one erg. It requires approximately
5000 ergs to lift a 5c coin a height of one centimeter. Since a dyne is only
about one 500,000th part of a pound of force, and a centimeter about one 30th
part of a foot it follows that one erg is about one 15,000,000th of a
foot-pound. (Exactly, one erg equals one 13,560,000th of a foot-pound.) For
practical purposes a larger unit than the erg is required, hence the joule
is used. One joule is equal to 10,000,000 ergs; one joule equals 0.738
foot-pounds; one foot-pound equals 1.356 joules.
Power is the amount of work that is done in
a unit of time.
English System:
If work is done at a rate of 550
foot-pounds per second, or 33,000 foot-pounds per minute, this constitutes a
rate of one horse-power (h.p.).
A rate of doing work of one joule per
second is a watt. One thousand watts is one kilowatt (kw.).
One kilowatt equals 738 foot-pounds per second. One kilowatt equals 1.341
horse-power. One horse-power equals 0.746 kilowatts. A kilowatt-hour
(kw.-hr.) is the amount of work done' by a kilowatt of power in
one hour; thus a kilowatt-hour is a unit of work instead of power, and is equal
to 1,000 joules per second for one hour. Thus one kilowatt-hour (kw.-hr.) equals
3,600,000 joules; thus one kilowatt-hour (kw.-hr.) equals about 2,655,000 foot
pounds. The kilowatt hour as given above is exactly the kilowatt-hour for which
one pays his monthly electric light bill. One kilowatt-hour will lift a one ton
weight a height of a quarter of a mile, or a height greater than the Empire State Building in New York (1248 feet).