Basic Metric Unit Of Measure For Volume example essay topic

Biology: The Science of Our Lives Biology literally means 'the study of life'. Biology is such a broad field, covering the minute workings of chemical machines inside our cells, to broad scale concepts of ecosystems and global climate change. Biologists study intimate details of the human brain, the composition of our genes, and even the functioning of our reproductive system. Biologists recently all but completed the deciphering of the human genome, the sequence of acid (DNA) bases that may determine much of our innate capabilities and predispositions to certain forms of behavior and illnesses. DNA sequences have played major roles in criminal cases (O.J. Simpson, as well as the reversal of death penalties for many wrongfully convicted individuals), as well as the impeachment of President Clinton (the stain at least did not lie). We are bombarded with headlines about possible health risks from favorite foods (Chinese, Mexican, hamburgers, etc.) as well as the potential benefits of eating other foods such as cooked tomatoes.

Infomercials tout the benefits of metabolism-adjusting drugs for weight loss. Many Americans are turning to herbal remedies to ease arthritis pain, improve memory, as well as improve our moods. Can a biology book give you the answers to these questions? No, but it will enable you learn how to sift through the biases of investigators, the press, and others in a quest to critically evaluate the question. To be honest, five years after you are through with this class it is doubtful you would remember all the details of. However, you will know where to look and maybe a little about the process of science that will allow you to make an informed decision.

Will you be a scientist? Yes, in a way. You may not be formally trained as a science major, but you can think critically, solve problems, and have some idea about what science can and cannot do. I hope you will be able to tell the shoe from the shin ola. The Scientific Process Scientists make progress by using the scientific method, a process of checking conclusions against nature.

After observing something, a scientist tries to explain what has been seen. The explanation is called a hypothesis. There is always at least one alternative hypothesis. A part of nature is tested in a 'controlled experiment' to see if the explanation matches reality.

A controlled experiment is one in which all treatments are identical except that some are exposed to the hypothetical cause and some are not. Any differences in the way the treatments behave is attributed to the presence and lack of the cause. If the results of the experiment are consistent with the hypothesis, there is evidence to support the hypothesis. If the two do not match, the scientist seeks an alternative explanation and redesigns the experiment.

When enough evidence accumulates, the understanding of this natural phenomenon is considered a scientific theory. A scientific theory persists until additional evidence causes it to be revised. Nature's reality is always the final judge of a scientific theory. Science is an objective, logical, and repeatable attempt to understand the principles and forces operating in the natural universe. Science is from the Latin word, scientia, to know.

Good science is not dogmatic, but should be viewed as an ongoing process of testing and evaluation. One of the hoped-for benefits of students taking a biology course is that they will become more familiar with the process of science. Humans seem innately interested in the world we live in. Young children drive their parents batty with constant 'why' questions. Science is a means to get some of those whys answered. When we shop for groceries, we are conducting a kind of scientific experiment.

If you like Brand X of soup, and Brand Y is on sale, perhaps you try Brand Y. If you like it you may buy it again, even when it is not on sale. If you did not like Brand Y, then no sale will get you to try it again. In order to conduct science, one must know the rules of the game (imagine playing Monopoly and having to discover the rules as you play! Which is precisely what one does with some computer or video games (before buying the cheat book). The scientific method is to be used as a guide that can be modified. In some sciences, such as taxonomy and certain types of geology, laboratory experiments are not necessarily performed.

Instead, after formulating a hypothesis, additional observations and / or collections are made from different localities. Steps in the scientific method commonly include: 1. Observation: defining the problem you wish to explain. 2. Hypothesis: one or more falsifiable explanations for the observation.

3. Experimentation: Controlled attempts to test one or more hypotheses. 4. Conclusion: was the hypothesis supported or not? After this step the hypothesis is either modified or rejected, which causes a repeat of the steps above. After a hypothesis has been repeatedly tested, a hierarchy of scientific thought develops.

Hypothesis is the most common, with the lowest level of certainty. A theory is a hypothesis that has been repeatedly tested with little modification, e.g. The Theory of Evolution. A Law is one of the fundamental underlying principles of how the Universe is organized, e.g. The Laws of Thermodynamics, Newton's Law of Gravity. Science uses the word theory differently than it is used in the general population.

Theory to most people, in general nonscientific use, is an untested idea. Scientists call this a hypothesis. Scientific experiments are also concerned with isolating the variables. A good science experiment does not simultaneously test several variables, but rather a single variable that can be measured against a control. Scientific controlled experiments are situations where all factors are the same between two test subjects, except for the single experimental variable.

Consider a commonly conducted science fair experiment. Sandy wants to test the effect of gangsta rap music on pea plant growth. She plays loud rap music 24 hours a day to a series of pea plants grown under light, and watered every day. At the end of her experiment she concludes gangsta rap is conducive to plant growth.

Her teacher grades her project very low, citing the lack of a control group for the experiment. Sandy returns to her experiment, but this time she has a separate group of plants under the same conditions as the rapping plants, but with soothing Led Zeppelin songs playing. She comes to the same conclusion as before, but now has a basis for comparison. Her teacher gives her project a better grade. Metric System Unit System of Measurement The Metric system was developed in France during the Nepolianic reign of France in the 1790's. The metric system has several advantages over the English system which is still in place in the U.S. However the scientific community has adopted the metric system almost from its inception.

In fact, the metric system missed being nationalized in this country by one vote in the Continental Congress in the late 1700's or early 1800's. The advantages of the Metric system are: It was based on a decimal system (ie: powers of ten). Therefore, it simplifies calculations by using a set of prefixes which we will discuss in a few minutes. It is used by most other nations of the world, and therefore, it has commercial and trade advantage.

If an American manufacturer that has domestic and international customers is to compete, they have to absorb the added cost of dealing with two systems of measurement. Let's now take a few minutes and speak of the useful set of 'prefixes' used in the metric system sometimes referred to as the System Internationale (SI). One of the mathematical advaita get of the metric system is its combination of metric terminology with its decimal organization. There are several prefixes that are associated with a decimal position and can be attached to the base metric unit in order to create a new metric unit. The knowledge of the decimal meaning of the prefix establishes the relationship between the newly created unit and the base unit. For example: the prefix 'kilo' means 103 or 1000 so if I take a mythical base unit like the 'bounce' and I attach the kilo prefix in front, I create a new unit called the 'kilo bounce'.

In addition, the relationship between the two units is now well established. Since I know that 'kilo' means 1000 then one kilo bounce unit is the same as (or equal to) 103 bounce units. The prefixes that are most important are listed below along with their decimal and exponential equivalents: Prefix decimal equivalent exponential equivalent Pico 0.000000000001 10-12 Nano 0.000000001 10-9 Micro 0.000001 10-6 Milli 0.001 10-3 Cent i 0.01 10-2 Deci 0.1 10-1 no prefix 1.0 100 Deka 10.0 101 Hec to 100.0 102 Kilo 1000.0 103 Mega 1,000,000.106 Giga 1,000,000,000.109 There are several dozen prefixes used but these above are most commonly used in Science measurements. Now, we will be looking at the metric units of measurement in five separate areas of measure.

The abbreviations of each unit will appear in parenthesis when the unit is first mentioned in the lesson. The types of measure discussed in this mini-lesson are: 1. Mass 2. Dimension 3. Volume 4. Time 5.

Area The last two will be briefly dealt with. Mass Measurement The measure of mass in the metric system has several units that scientists use most often. The gram is the standard unit of mass in the metric or SI system. The gram (g or gm) is roughly analogous to the English dry ounce. It takes about 29 grams to equal one dry ounce. A larger mass unit analogous to the English pound is the kilogram.

The kilogram is the same as 1000 grams and represents 2.2 pounds in mass. Other metric mass units include: 1. the centigram (cg) 2. milligram (mg) 3. microgram mg 4. (ng). The basic instrument used to measure mass is the mass balance. There are some digital balances today that can display the mass of an object in several different mass units both in the English and Metric systems. Dimensional Measurement Now let us go over dimensional measurement that is measure of length, width, and height. The basic metric unit of dimension is the meter (m).

The meter is analogous to the English yard. A meter is equal to slightly more than a yard (about 10% larger). One meter is equal to 1.09 yards or 39.36 inches. A larger metric unit used often is the kilometer (km) which is analogous to the English mile. One kilometer is equal to 0.62 miles.

In countries where the metric system is the national standard, signposts and posted speed limits are in km or km per hour. For example, the most common speed limit in Mexico is 100, but that is 100 km / hr or about 60 miles per hour!! Other dimensional units include the 1. decimeter (dm) 2. centimeter (cm) which is analogous to the English inch. One inch is equal to 2.54 cm 3. millimeter (mm) 4. micrometer (mm) 5. nanometer (nm). The nanometer is used when very small interatomic or intermolecular distances are called for. The main instrument in the science lab that measures dimension is the metric ruler.

The metric ruler comes in various sizes. There is the 150 mm ruler and a metric meter ruler which are used most. However, all metric rulers are calibrated the same. The numerically numbered positions (major calibrations) are equal to centimeter marks, and then there are ten equally spaced positions (minor calibrations) in between each of the numbered positions each of which are equal to 0.1 cm (1 mm). According to this calibration, one can record measurements with one position of estimation to the nearest 0.01 cm. Another instrument most often used in Physics labs is called a micrometer.

As the name implies it can measure to the nearest micrometer and is used for very precise measurements of diameters. Volume Measurement The third type of measure is measure of volume. Actually we can break this down into the measure of 1. solid volume (regular and irregular) 2. fluid (liquid and gas) volume Volumes of Regular Solids Regular Solids are those that have well defined dimensions of length, width, height, and diameter. These can first be measured with a suitable dimensional instrument like a metric ruler.

Then a suitable geometrical formula might be applied to get the volume. For example, if the solid was rectangular shaped, you would measure the dimensions of the rectangle and then use the formal V = l X w X h in order to determine the volume of the rectangle. Volumes of Irregular Solids Irregularly shaped solids do not have well defined dimensions and therefore can't use the above method of determining its volume. However, one can use the principle of liquid displacement that says since two chucks of matter can't occupy the same space at the same time that when placed together one object will displace the other. If we measure a certain volume of water in a graduated cylinder to be 5.0 cc and we immerse some pieces of metal into the water, the reading on the graduated cylinder might read 14.0 cc. By subtracting the two readings we now have how much displacement of the water there was when the metal fragments were immersed.

That displacement would be equal to the volume of the metal fragments. 14.0 - 5.0 = 9.0 cc = volume of metal fragments Measurement of Fluid Volumes Let's now discuss measure of fluid volume. There are several instruments used to directly measure fluid volumes. The graduated cylinder is the most commonly used in the lab. However, there are several others.

The pipe t, buret, and volumetric Flask measure fluid volumes more precisely than most graduated cylinders. The basic metric unit of measure for volume is the liter (l) unit. The liter is analogous to the English quart. One liter being the same as 1.06 quarts.

It is basically a fluid volume unit as is the smaller metric unit called the milliliter (ml). The milliliter is analogous to the English fluid ounce. One fluid ounce is equal to about 30 ml. Other metric units of volume that are more often associated with volumes of solids is the cubic centimeter (cc or cm 3) which is equal to a milliliter. To a careless observer the cc may look like a dimensional unit since it has the word 'centimeter' in it. However, it also has the word 'cubic' which always indicates a volume unit.

You can think of a cubic centimeter as a cube 1 cm on each edge. The volume of such a cube would be 1 cm X 1 cm X 1 cm or 1 cm 3. We also use the cubic meter (m 3) often in science to measure large volumes in space. Actually, any dimensional relationship such as 100 cm = 1 m can be used to derive a volume unit relationship simply by cu being BOTH sides of the relationship so for example: 100 cm = 1 m cubed would be: (100 cm) (100 cm) (100 cm) = (1 m) (1 m) (1 m) or 1 X 106 cm 3 = 1 m 3 You can even do this with English dimensional relationships that result in a newly created volume relationship.

For example: 1 ft = 12 in. If we cubed both sides we would have: (1 ft) (1 ft) (1 ft) = (12 in) (12 in) (12 in) or 1 ft 3 = 1728 in 3 Area Measurement Area measurement relationships are similar to volume relationships except you square both sides of the dimensional relationship. For example if we wanted to know the relationship between square cm and square m we could begin with the following dimensional relationship between cm and m 100 cm = 1 m Now square bo the sides (100 cm) 2 = (1 m) 210,000 cm 2 = 1 m 2 In summary, dimensional measurement is one dimensional, area measurement is two dimensional and volume measurement is three dimensional in scope.