Fundamental & Derived Quantities

Science is concern with making sense out of the environment . The early stages of this “ search for sense” usually involve objects in the environment things that can be seen or touched. These could be objects you see every day, such as a glass of water, a moving automobile, or a running dog. One way is to assume that all events in nature have natural causes. We can then try to arrange a series of observation or tests to learn what those causes are. Science is the word that we apply to this process. The goal of science is to understand the world around us. There are, however, many important fields of human endeavor that study the world around us but are not considered sciences.

Scale  is anything that can be measured and expressed in value. If the terms of the direction and value, magnitude grouped into two, namely:

1.   Scalar or fundamental quantity, the quantity that only has value without having direction. Example: mass, length, time, energy, effort, temperature, pace and distance. 
2. Vector or derived quantity, the amount of which has a value and a direction. Example: style, weight, strong currents, velocity, acceleration and displacement.

Meanwhile, based on the type of unit, size grouped into two, namely:

a.    Scale Basic

Principal amount is the amount that the unit has been set in advance and are not composed of other quantities. Principal amount of seven scale. Seven units are based on the principal amount and the international system of units (SI) as indicated in the following table.

International system of units (SI) unit system means that the most widely used around the world, with international best practice.

b. Scale Derivatives 

 Scale derivative is a combination of units of the principal amount. Examples of broad scale derivative is a rectangular area. Area equal to the length multiplied by width, where length and width are both units of length. Note the magnitude derived tables, units and dimensions below.

 

Unit is a measure of a quantity used to measure. The types of units namely:

a. Raw Unit 

    Standard unit is the unit that has been recognized and its use internationally agreed    with the so-called tau international units (SI).

Example: meter, kilogram, and second.

International system of units is divided into two, namely:

1. MKS system (Meter Kilogram Sekon)

2. System CGS (Centimeter Gram Second)

b. Unit Not Raw 

    Non-standard unit is the unit that is not recognized internationally and is only used in a certain area. Example: fathoms, feet, legs, arms, tumbak, brick and steps 

Science works best when scientists every where read each other’s paper, check each other’s experiment and argue about what those experiments mean. Because most experiment involve measurement in which to present their findings. Scientists use the metric system of length, volume, mass, and temperature when describing experiments and data. The metric system is a decimal system based on the certain standards and scale on multiples of 10. The metric system is also known as the International system of Units or SI.

1. Length

    The basic unit of length in the metric system is a meter (m). One meter is roughly equivalent to 39,4 inchies, alittle longer than a yard. To measure objects and distance much larger or smaller than a meter by multiples of 10. A centimeter (cm) is 1/100 of a meter-about the width of the nail on your pinky. As you may have guessed, the prefix centi- means on hundredth. A milimeter (mm) is 1/1000 of a meter. The length-such as those used to describe living thing cells, pieces of cells, and molecules. To measure the distance much greater than a meter, scientists used a unit called the kilometer (km). One kilometer is contain 1000 meter and use prefix kilo-

 

2.    Volume

       Volume is the amount of space an object occupies. The basic metric unit of volume are the liter (L) for liquid and the cubic centimeter (cc or m³) for solids. A liter contain slighty more liquid than a quart. To measure small volume of liquids, scientists use fraction of a liter called milliliters (mL). There are 1000 milliliters in a single liter. A cubic centimeters is the volume of a solid that measures 1 cm by 1 cm by 1 cm. Keep in mind that 1 milliliter is equal in volume to 1 cubic centimeter or 1 mL=1 cc.

 

3.    Mass and Weight

        Mass is measure of the amount of matter in an object. Weight is a measure of the pull of gravity on that mass. In outer space, the weight of an object may vary with it’s position, but its mass always remain the same. On earth’s surface, however, an object’s mass and weight can usually be considered constant and are often used interchangeably. The basic metric unit scientists used to describe mass is the kilogram (kg). One kilogram is equal to approximately 2,2 pounds. The mass of small objects is measured in grams (g). One gram is 1/1000 of kilograms.

 

4.    Temperature 

        The metric system measures temperature using the Celcius scale (⁰C). On this scale water freezes at 0⁰C and boils at 100⁰C. Each celcius degree, therefore, represents exactly 1/100 of the temperature range between the freezing and boiling points of water. Normal human body temperature is about 37⁰C and comfortable room temperature is about 21⁰C. 

Measurement is something that is used to measure a quantity. A wide range of measuring instruments have a certain level of accuracy. It relies on the smallest scale measures. The smaller the scale indicated on the gauge, the higher precision instruments. Some examples of measuring instruments in accordance with the magnitude, namely:

a. Length Measurement

1. Ruler (ruler)

The bar is a long style with precision measuring up to 0.1 cm or 1 mm. On the reading scale, the position of the observer's eye should be perpendicular to the scale ruler in reading. 

2. Calipers

Calipers used to measure an object with a length of less than 1mm. Smallest scale or level of measurement accuracy up to 0.01 cm or 0.1 mm. Generally, calipers are used to measure the length of an object, the diameter of the ball, Ebal coins, and the inner diameter of the tube. Scale calipers have two readings, namely:

              a).   Main Scale / fixed, which is contained in the fixed jaw vernier caliper. 

 b). Vernier scale, the scale contained in the sliding jaw Dapa shifted / moved.

3. micrometer Screws

A micrometer screw gauge length with the smallest degree of accuracy. It is 0.01 mm or 0.001 cm. Smallest scale (scale Nonius) on micrometer screw located on the sliding jaw, while the major scale are the fixed jaw. Micrometer screw is used to measure the diameter of a round object and a very thin plate.

a.    Mass Measurement

Measuring instruments used to measure the mass of an object is the balance sheet. Based on how it works and the accuracy balance sheet is divided into three, namely:
1. Digital balance, the balance that works with electronic systems. Accurate and up to 0,001 g

2. O'Hauss balance, ie the balance sheet with a level of accuracy up to 0:01 g.

3. Equal arm balance, ie the balance sheet with a level of accuracy up to 1 mg or 0.001  

c.  Time Measurement 

     International unit for time is seconds or seconds. The second standard is the time needed by Cesium-133 atom to vibrate 9,192,631,770 times as much. The tools used to measure time, among other sundials, clocks, watches (with a precision of 1 second), and a stopwatch (nearest 0.1 second).