Showing posts with label Physics. Show all posts
Showing posts with label Physics. Show all posts

Sunday, January 6, 2013

History of Law of Motion Objects

A discussion of the laws of motion of objects in recorded history begins from a Greek philosopher named Aristotle. Scientific thinking is what dominates Aristotle's views on the motion for many - years. His views on the motion of objects accepted by the public because it seems to support this view seems to what people observe in nature. Aristotle's view that emerged at that time was that the weight affect falling objects. He argues that if two objects of different mass are dropped at the same time from the same height above the surface of the earth, then the heavier object will reach the surface of the earth faster than lighter objects. He also asserted that the force should continue to be applied to keep an object to keep moving (this concept against with the law of inertia). Though both Aristotle was wrong but it took a long time to deny it.

Ibu Sina (Avicenna)


Meanwhile in Persia science is developing rapidly, especially among Muslims. One is the famous scientist Ibn Sina (980-1037). Ibn Sina (Avicenna) in his book titled Teasing and Notification (Isharat wa Tanbihat) said "You know if the object is left unaffected by external influences, it remains as it is", if an object is not affected by outside influences then it will fixed (in original condition).

A few years later Abul Barakat bin Hebattullah Malacca (1087-1164) stated in his book Al-Moatabar fil Hekma (Wisdom Considerations) meaning as follows: "The strongest power moves fast and takes a short time. The Stronger the power, the faster the power, and the shorter the time. If the power does not Decrease, Decrease the speed does not, either. " In chapter fourteen entitled the Vacuum, he pointed out that "The faster the speed, the Stronger the power. The Stronger the power that pushes the object, the faster the speed of the object at the move, and the shorter the time spent for covering the distance ".

Additionally Abul Barakat is still in the same book states that "" In the wrestling arena, everyone has a practiced force against the other. If one of them retreated, this does not mean that his power disappears, but this retreated power still exists, Because without it the second one would not need it to influence the first one ".

Ibn Al Hayytham

Ibn Al-Hayytham (965 - 1039) in his book The Scenes (Al-Manather) states "The moving object is encountered by an obstruction, and if this forces remains, this moving object retreats in the opposite direction in the same practiced speed by the first object and According to the power of obstruction ".

Another opinion was delivered by Imam Fakhr El-Din Al-Razi (Mohamed Abdullah bin Omar bin al-Hassan from 1150 to 1210). In his book The Eastern Disciplines in Theology and Natural Sciences (Al-Al-Mashrikayyah Mabaheth Illm fi al-wa Al-Tabi'yyat Illaheyyat) states that "the circle pulled by two equal forces until it stops in the middle, it is taken for granted that each forces has practiced an action that obstructs the other ".

Galileo Galilei


In the western world, Galileo Galilei (1564 - 1642) tried to refute Aristotle's claim that the heavier object will reach the surface of the earth faster than lighter objects when dropped at the same time from the same height above the earth's surface. Galileo conducted two experiments. In the first experiment, he dropped a cannonball and a rifle bullet (bullet shaped ball) simultaneously from the Leaning Tower of Pisa. Aristotle's theory predicts that the shells (more severe) first up to the ground level compared with a rifle bullet. But Galileo discovered that two objects fall at the same speed and hit the ground at approximately the same time.
Some historians question whether Galileo ever do that experiment in the tower of Pisa, but he was followed by a second phase of the work has been well documented. The second experiment involved a bronze balls of different sizes in rolled slant board. Galileo noted how far the ball will roll at each interval of one second. He found that the size of the ball is not important - the rate of descent along the path remains constant. From this, he concluded that objects in free fall accelerate the uniform apart from the masses, as long as external forces, such as air resistance and friction, can be minimized.

René Descartes

René Descartes (1596 - 1650) a French philosopher argued about inertial motion. In his book "Principles of Philosophy," proposed three laws of nature. The first law states "that every thing in his power so far, always remained in the same state. Consequently if once moving it will always move. Second law states that" all movement "from itself" is along the lines of bullets. "From the second law can be concluded that if an object is affected by force (force) generated by himself then there are two possibilities, the first when the object is stationary, then the object would remain silent. Secondly if a moving object will continue moving in a straight line. It Newton's first law is clearly stated in a book in 1644, when Newton was a baby.

Isaac Newton

In 1687, Isaac Newton (1642-1727) declared three physical laws that form the basis of classical mechanics.

1. First Law: Every object will have a constant velocity unless a non-zero resultant force acting on the object. Meaning if the resultant force is zero, then the center of mass of an object remains at rest or moving at a constant speed (not accelerating).

2. Second Law: A body of mass M having the resultant force of F will accelerate a direction similar to the direction of the force, and the magnitude is proportional to F and inversely proportional to M. or F = Ma. It could also mean the resultant force acting on an object is equal to the derivative of the linear momentum of the object with respect to time.

3. Third Law: action and reaction force of two objects have the same magnitude, the direction reversed, and the line. This means that if an object A, which gives a force of F on object B, then object B will give a force of-F to object A. F and-F have the same magnitude but different direction. This law is also known as the action-reaction law, with F called the action and-F is a reaction.

If we look carefully from Newton's third law is apparently no connection with the statement - a statement of the previous Muslim scholars. Newton's first law is similar to the statement of Ibn Sina. Newton's second law is identical to the statement Hebattullah bin Abul Barakat of Malacca, and Newton's third law and its statement proposed by Abul Barakat bin Hebattullah Malacca, Ibn Al-Hayytham, and Fakhr El-Din Al-Razi. Nevertheless, Newton was the first to declare the third law of mathematics.

Thus seen that Muslim scientists was instrumental to the development of the science and technology developed at this time.

Friday, January 4, 2013

Magnitude Physics (Principal Amount and the amount of derivatives)

In everyday life, we often hear the term length, time, temperature, and weight. Apparently unconsciously we have learned about the physics discussion of "Magnitude".

However, what is the definition of this magnitude? From various sources I've read, the definition of magnitude in physics is anything that can be measured with numbers and have the exact unit.

Of the many scale as we know, the amount is divided into two principal groups: the scale and magnitude of the derivative. The definition of principal amount is the amount that has been determined in advance (on the set) based on the consensus of the physicist. In Indonesia there is a term "nine basic", in physics as well as it turns out there is a term, which is "the seven principal amount". Seven principal amount consists of scale length, time, mass, electric current, the number of molecules, and light intensity.

In addition to the amount - the amount of principal that has been stated above, is also called the derivative. The definition of the magnitude of the derivative is the amount derived from one or more of the principal amount. For example, the volume derived from the scale length; style derived from the amount of mass, length and time; velocity derived from the length and time scale. More details see table quantities and units are also at the bottom of this post.

Scale indicate the nature of the object. This trait is expressed in numbers through the measurement results. Because the magnitude scale is different from the other, then set the units for each scale. Unit also suggests that each scale is measured in different ways. In order for the uniformity, the units for scale - physical quantities based on the International System of units (SI). The SI unit is taken from the metric system has been used in France after the revolution of 1789.

Here is the scale - physical quantities and their units:

Basic SI quantities
Quantity
Dimension
Alternatives
Root definition and Notes
Length/distance m m meter
Mass kg kg kilogram
Time s s second
Curren, electric A A ampere
Temperature K K kelvin
Quantity of subtance mol mol mole
Luminosity/Luminous Intensity cd cd candle