CHAPTER 6 Electindo.com PHYSICS FOR JUNIOR HIGH SCHOOL VII

Electindo.com PHYSICS FOR JUNIOR HIGH SCHOOL VII THE SUBSTANCE EXPANSION A.THE SOLID EXPANSION  THE LENGTH EXPANSION The expansion that only influences the increase of length is called length expansion. One of the instruments that is commonly used for observing the length expansion is Musschenbroek. The expansion could be observed by checking the scale that is pointed by the pointer, the bigger the expansion is, the bigger the rotation of pointer in the scale will be. The increase of length of one substance physically :  Directly proportional with the former length  Directly proportional with the temperature fluctuation  Depends on the kind of substance itself.

Electindo.com PHYSICS FOR JUNIOR HIGH SCHOOL VII THE SUBSTANCE EXPANSION  The length expansion coefficient of some substances are provided in the following table :  The length expansion coefficient of aluminum is much bigger than both the copper and iron, so that the biggest length increase occurs at al  uminum (Al), copper (Cu), iron (Fe). It means that the length expansion coefficient is Al > Cu > Fe. SubstanceCoefficient of length expansion Aluminum0, Bronze0, Iron0, Graphite0, Glass0, Pyrex glass0, Ice0, Steel Copper 0, ,000017

Electindo.com PHYSICS FOR JUNIOR HIGH SCHOOL VII THE SUBSTANCE EXPANSION B.THE BROAD EXPANSION broad expansion can be observed at the window glass, when it is in the high temperature, the glass temperature becomes high, so that the expansion happening. The glass expands bigger than its frame, as the result, the glass looks exactly fit to the frame. An object that is expanding will be bigger than it is at the first. The expansion that happens in a solid object if the thickness is much smaller compared with its length and its width, the broad expansion will happen. The formula for broad expansion The broad increase that happens in the high-temperature object can be stated mathematically in the following equation : before after

Electindo.com PHYSICS FOR JUNIOR HIGH SCHOOL VII THE SUBSTANCE EXPANSION B.THE VOLUME EXPANSION if the heated solid is something like a ball-shaped object, so the object will get volume expansion. In the volume expansion, the expansion is considered to all sides. To determine the expansion of solid object, the expansion coefficient is is three times the length expansion coefficient, it can mathematically stated as follows : To know the volume increase of one solid object, we can use this formula : Volume of the heated object is : or

Electindo.com PHYSICS FOR JUNIOR HIGH SCHOOL VII THE SUBSTANCE EXPANSION B.LIQUID EXPANSION The liquid expansion is related to pressure expansion because the temperature increase. The confluence of liquid, solid, and gas is called triple point. C.GAS EXPANSION The process of expansion in gas substance is the same process that occurs in liquid substance, where it only occurs space expansion. The gas expansion is bigger than the liquid expansion, to count the amount of volume expansion, we can use the following equation : Vt – V 0 = V 0. γ. Δ T Δ V = V. γ. Δ T... (3 – 11) Pressure(p) liquid Critical point steam Triple point solidity

Electindo.com PHYSICS FOR JUNIOR HIGH SCHOOL VII SUBSTANCE EXPANSION  The substance expansion is divided into 3 kinds as follows : 1.Gas expansion in constant temperature (isothermal), 2.Gas expansion in constant pressure, and 3.Gas expansion in constant volume. D.THE SUBSTANCE EXPANSION IN REAL LIFE The substance expansion can be easily found in our daily life. The knowledge of expansion can be very useful to make easier our works. Moreover, we can prevent unwanted phenomenon caused by substance expansion. 1.The utilization of Bimetal 2.Pengelingan 3.The attachment of wheel rim 4.The attachment of electric and telephone network 5.The fitting of window glass

Electindo.com PHYSICS FOR JUNIOR HIGH SCHOOL VII