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WATER PRESSURE
WATER PRESSURE
There are a lot of definitions about volume. According to American Heritage
Dictionary, volume in the term of measurement can be defined as two definitions.
First, volume is the amount of space by a three-dimensional object or region of
space. Second, volume is the capacity of such a region or of a specified container.
Hurd, Silver, and Bacher, in their book, Prentice Hall Physical Science, define
volume as the amount of space on an object takes up. From the three definitions, we
can conclude that volume is the capacity of a specified object.
Based on Hurd, Silver, and Bacher, the basic unit of volume in metric system is
the Liter (L). Liters and milliliters are used to measure the volume of liquids. The
metric unit used to measure the volume of solids is called the cubic centimeter
(cm3). Cubic centimeters often are used in measuring the volume of liquids as well
as solids. 1 cm3 is same as 1 milliliter or 1X 10-3 L.
There are two ways to measuring the volume of an object in form of solid, based
on the shape of the object. Volume of a solid that has rectangular shape (or also
called as regular solid) can be measured by multiplying the length of the solid times
the width of the solid times the height of the solid. So, volume = height X length X
width. Volume of a not-rectangular shape (or irregular shape) can be measured with
the using of graduated cylinder. The volume is same as the increasing volume after
the solid filled in the graduated cylinder that had been filled with water before.
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A. LENGTH
According to Roget’s II: The New Thesaurus, length is the measure of how far or
long something goes in space, time, or degree. American Heritage Dictionary said
that length is the measured distance or dimension.
The basic unit of length in the metric system is meter (m). A meter is equal to
about 39, 4 inches. The prefix in front of the word of ‘meter’ refers to the tenmultiplication unit of meter. For example, centimeter, centi- means one-hundredth.
So, they are 100 centimeters in a meter. Other example, is kilometer, kilo- means
one thousand. So, there are 1000 meters in a kilometer.
Tools to measure length are metric ruler and meterstick. A metric ruler is divided
into centimeters. A meterstick is one meter long and contains 100 centimeters.
Vernier caliper can also used to measure the length of an object in the shape of
circular or ball.
To use metric ruler or meterstick, an observer just need to place the zero number
of ones in a point of the measured object and read the number pointed by the ones
in the other object’s point.
Vernier caliper has part named jaws and two scales named main scale and nonius
scale. Jaws are used to press the measured object when measurements occur. Main
scale is typed in the constant part of the caliper and the nonius scale is typed in the
impermanent part of the caliper. First step to use vernier caliper is press the object
between the jaws. Then lock the position by spin the tighten screw. Read the main
scale in the constant part. Then add the number pointed by the main scale with the
decimal number pointed by the nonius scale.
B.
MASS
Based on the American Heritage Dictionary, mass is the quantity of matter that a
body contains, not dependent on gravity and therefore different from but
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proportional to its weight. According to Roget’s II: The New Thesaurus, mass is a
separate and distinct portion of matter. Hurd, Bacher, and Silver say that mass is a
measure of the amount of matter in an object.
According to Hurd, Bacher, and Silver, the basic unit of mass in metric system is
the kilogram (kg). The kilogram unit is used to measure the mass of large object. To
measure the small object, the gram (g) is used. The mass of even smaller objects is
measured in milligram (mg).
One of the most common tools used to measure mass in grams is the triple-beam
balance, although the spring balance can also be used. There are two kinds of triplebeam balance, depend on the place where the measured-object placed; one with the
lying pan and one with the weighing-pan. A triple-beam balance has three beams.
Each beam is marked, or calibrated, in grams. The front beam is the 10-gram beam
that divided into 10 segments of 1-gram each. The back beam, often called the 500gram beam, is divided into 5 segments of 100 grams each. The middle beam, or
100-gram beam, is divided into 10 segments of 10 grams each.
C. ELECTRICAL RESISTANCE
Electrical resistance is the resistance of an electric circuit. The Electrical
resistance value is depends on the value of the resistance constant of
a resistor
material, the surface-wide of the resistor, & the length of the resistor. The metric
unit for electrical resistance in scientific measurement is ohm. In an electric circuit,
the value of electrical resistance equal to that of a conductor in which a current of
one ampere is produced by a potential of one volt across its terminals.
The electrical resistance can be measured with using the ohmmeter or multimeter.
Multimeter is a tools that can be used to measure the electric resistance, voltage,
and electric current. To measure the electrical resistance by using the multimeter,
we should switch it to the ohmmeter function first and connect it to the whole
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electric circuit. The electrical resistance value can also be found by divide the value
of voltage with value of electric current.
A source addressed in http://www.multimeterwarehouse.com/usingamultimeter.htm said:
An ohmmeter does not function with a circuit connected to a power
supply. If you want to measure the resistance of a particular component,
you must take it out of the circuit altogether and test it separately.
Ohmmeters work by passing a small current through the component and
measuring the voltage produced. If you try this with the component
connected into a circuit with a power supply, the most likely result is that
the meter will be damaged. Most multimeters have a fuse to help protect
against misuse.
The resistance scale on an analogue meter is normally at the top, it is an unusual
scale because it reads backwards and is not linear (evenly spaced). This is
unfortunate, but it is due to the way the meter works.
1. Set
the
meter
to
a
suitable
resistance
range.
Choose a range so that the resistance you expect will be near the middle of
the scale. For example: with the scale shown below and an expected
resistance of about 50k
choose the × 1k
range.
2. Hold the meter probes together and adjust the control on the front of the
meter which is usually labelled "0
ADJ" until the pointer reads zero (on
the right). If you can't adjust it to read zero, the battery inside the meter
needs replacing.
3. Put
the
probes
across
the
component.
Avoid touching more than one contact at a time or your resistance will
upset the reading.
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Reading analogue resistance scales. For resistance use the upper scale, noting
that it reads backwards and is not linear (evenly spaced). Check the setting of the
range switch so that you know by how much to multiply the reading.
D. VOLTAGE
Based on the American Heritage Dictionary, voltage is the electromotive force or
potential difference, usually expressed in volts. American Heritage Dictionary also
said that volt is the unit of electric potential and electromotive force equal to the
difference in potential needed to cause a current of one ampere to flow through a
resistance of one ohm.
The voltage can be measured with using the voltmeter or multimeter. Multimeter
is a tools that can be used to measure the electric resistance, voltage, and electric
current. To measure the voltage by using the multimeter, we should switch it to the
voltmeter function first and connect it to the whole electric circuit. The voltage
value can also be found by multiply the value of electric resistance with value of
electric current.
A source addressed in http://www.multimeterwarehouse.com/usingamultimeter.htm said:
This time, you do not need to break the circuit. The voltmeter is connected
in parallel between the two points where the measurement is to be made.
Since the voltmeter provides a parallel pathway, it should take as little
current as possible. In other words, a voltmeter should have a very HIGH
resistance.
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Measuring voltage with a multimeter:
1. Select a range with a maximum greater than you expect the reading to be.
2. Connect the meter, making sure the leads are the correct way round.
3. If the reading goes off the scale: immediately disconnect and select a higher range
E.
ELECTRIC CURRENT
According to the American Heritage Dictionary, electric current is a flow of
electric charge, or, the amount of charge flowing past a specified circuit point per
unit time. Metric unit for electric current in scientific measurement is ampere.
Based on American Heritage Dictionary, ampere is a unit of electric current
strength, equal to a flow of one coulomb per second.
The electric current can be measured with using the ammeter or multimeter.
Multimeter is a tools that can be used to measure the electric resistance, voltage,
and electric current. To measure the voltage by using the multimeter, we should
switch it to the amperemeter function first and connect it to the whole electric
circuit. The electric current value can also be found by divide the value of voltage
with value of electric resistance.
A source addressed in http://www.multimeterwarehouse.com/usingamultimeter.htm said:
To start with, you need to break the circuit so that the ammeter can be
connected in series. All the current flowing in the circuit must pass
through the ammeter. Meters are not supposed to alter the behaviour of the
circuit, or at least not significantly, and it follows that an ammeter must
have a very LOW resistance.
Measuring electric current with a multimeter
1. Select a range with a maximum greater than you expect the reading to be.
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2. Connect the meter, making sure the leads are the correct way round.
3. If the reading goes off the scale: immediately disconnect and select a higher range
There are a lot of ways to measure the characteristics of object and the specified unit.
But, all of them use the basic rules named scientific notation. It is the way to ease in
expresses the measurement result, which used powers of 10. Absolutely, this notation
provides an easier way of writing large and small numbers and of doing arithmetic with them.
For example, ‘one million’ may be written as 106. But, the main nominal should express in
the range of 1 until 10, so 193.000 ca be written as 1,93 X 105 but can’t be written as 19, 3 X
104 or 0,193 X 106.
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