Una get light for Una state ?

Free update I just withdraw no need to deposit before you can withdraw

Introduction
Expansion means an increase in the size of an object. Most solids and liquids expand when heated and contract when cooled. When heat is provided to a body, its particles gets hot and vibrate with greater amplitude; space between particles becomes more prominent. This increase in amplitude causes an increase in the body’s length; this is called thermal expansion.

According to the kinetic molecular theory, when an object is heated, the molecules acquire more kinetic energies which enables them to overcome their intermolecular forces. Therefore, the vibrations of the molecules increase and their displacements about their mean positions increase. As a result of this, the average distance between the molecules of the substance becomes larger reading an increase in the size of the substance. This increase in the dimension of the heated object depends on the strength of the intermolecular forces. If their forces are stronger, the expansion will be small and vice versa.

The intermolecular forces are stronger in solids than in liquids and weakest in gases. Hence, when heat is applied, gases expand more than liquids and liquids expand more than solids. Each particular substance has an intermolecular force peculiar to it. Therefore, the addition of heat causes different expansions in different substances.

Linear, Area & Volume Expansivity
The linear expansivity (α) of a substance is the fractional increase in its length per degree change in temperature.

α = L2 - L1/L1 ( θ2 - θ1 )

'L' denotes Length

The area expansivity (β) of a substance is the fractional increase in area per degree change in temperature.

β = A2 - A1/A1 ( θ2 - θ1 ) | β = 2α

'A' denotes Area

The volume expansivity (γ) of a substance is the fractional increase in volume per degree change in temperature.

γ = V2 - V1/V1 ( θ2 - θ1 ) | γ = 3α

'V' denotes Volume

Note: Δθ = θ2 - θ1

As the case may be, 'e' = L2 - L1 | e = Extension

As the case may be, 'e' = A2 - A1 | e = Extension

As the case may be, 'e' = V2 - V1 | e = Extension

Effects & Applications
- Thermometer: Thermal expansion is used in temperature measurements in thermometers.

- Bimetal strip: It consist of two thin strips of different metals such as brass and iron joined together. On heating the strip, the brass expands more than the iron. This unequal expansion causes the bending of the strip. Bimetal strips are used for various purposes; they are used to measure temperature especially in furnaces and ovens. They are used in thermostats; a bimetal thermostat is used to control the temperature of the heater coil in an electric iron.

- Riveting: To join steel plates tightly together, red hot rivets are forced through holes in the plates. The end of hot rivets is then hammered. On cooling, the rivets contract and bring the plates tightly gripped.

- Removing tight lids: To open the cap of a bottle that is very tight, it can be immersed in hot water for about a minute. This causes the metal cap to expand and become loose.

- Railway tracks: They have gaps to make allowance for expansion due to a rise in temperature, otherwise the rails would buckle.

Other effects and applications of thermal expansion are found in fixing a metallic circular strip on a wooden tyre of a cart, buckling, expansion gap, anti-scalding valve, thermostat, cooking utensils, electric fire alarm, expansion of glass, sagging of telegraph wires, railway lines, steel bridges, etc.

Note: Thermal expansion is small but it does not always have an insignificant effect.

Real & Apparent Expansivity
Real expansivity of liquid is sometimes called cubic expansivity of liquid. It is defined as the increase in volume per unit degree rise in temperature. Unlike solids, liquids have no fixed length or surface area but take up the shape of the containing vessel. Therefore, in the case of liquids, we are concerned only with volume changes when they are heated.

Apparent cubic expansivity of a liquid is defined as the mass of the liquid expelled per unit divided by mass left or remaining when the temperature increases by 1oC. It is measured in K-1. Therefore,

Apparent cubic expansivity = mass of liquid expelled / (mass of liquid left x temperature rise)

Anomalous Expansion of Water
The way substances generally react to heat is that they expand when heated as the density decreases and vice versa takes place then they are cooled. This is not the case with water. The general tendency of cold water remains unchanged until 4oC. The density of water gradually increases as you cool it. When you reach 4oC, its density reaches a maximum. When you cool water further to make ice (i.e. 0oC), it expands with a further drop in temperature; meaning the density of water decrease when you cool it form 4oC to 0oC.

The effect of this expansion of water is that the coldest water is always present on the surface which is why ice is seen on the surface of water. Since water at 4oC is the heavest, this water settles on the bottom of the water body and the lightest i.e. the coldest layer accumulates on the top layer. This is why the top of the water is always the first to freeze. Since ice and water are both bad conductors of heat, this top layer of ice insulates the rest of the water body from the cold thereby protecting all the life in the water body.

What a world.u trust ur best friend with ur secret ,but ur friend hides hers from u.this is so bad

It is well,itsnot just easy