Area expansion is like a photographic enlargement

面积膨胀就像照片放大一样

Every linear dimension increases by the same percentage with a change in temperature, including holes. This assumes that the expanding material is uniform. .

每个线性尺寸随温度变化都增加相同的百分比，包括孔。这假设膨胀材料是均匀的。

Thermal expansion of an area can be calculated from the linear expansion coefficient.

面积的热膨胀可以由线性膨胀系数计算。

Table of expansion coefficients

膨胀系数表

Index

Expansion concepts

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Area Expansion

面积膨胀

Over small temperature ranges, the thermal expansion is described by the coefficient of linear expansion. If the linear expansion is put in the form

在较小的温度范围内，热膨胀可由线性膨胀系数描述。如果将线性膨胀表示为

then

然后

In most cases the quadratic term above can be neglected since the typical expansion coefficient is on the order of parts per million per degree C. The expression then becomes

在大多数情况下，上述二次项可以被忽略，因为典型的膨胀系数通常在每摄氏度百万分之一量级。因此，表达式则变为

which is equivalent to the expression at left.

这相当于左边的表达式

Will a hole in a uniform metal plate get larger or smaller with heating?

金属板上的孔在加热时会变大还是变小？

Index

Expansion concepts

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Volume Expansion

体积膨胀

Over small temperature ranges, the thermal expansion is described by the coefficient of linear expansion. If the linear expansion is put in the form

在较小的温度范围内，热膨胀可由线性膨胀系数描述。如果将线性膨胀表示为

then the expanded volume has the form

然后膨胀的体积形式为

In most cases the quadratic and cubic terms above can be neglected since the typical expansion coefficient is on the order of parts per million per degree C. The expression then becomes

在大多数情况下，上述二次项和三次项可以被忽略，因为典型的膨胀系数通常在每摄氏度百万分之一的数量级。因此，表达式则变为

Index

Expansion concepts

索引扩展概念

HyperPhysics***** Thermodynamics

HyperPhysics ***** 热力学

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