Elasticity弹性
Elasticity is the property of an object or material which causes it to be restored to its original shape after distortion. It is said to be more elastic if it restores itself more precisely to its original configuration. A rubber band is easy to stretch, and snaps back to near its original length when released, but it is not as elastic as a piece of piano wire. The piano wire is harder to stretch, but would be said to be more elastic than the rubber band because of the precision of its return to its original length. A real piano string can be struck hundreds of times without stretching enough to go noticeably out of tune. A spring is an example of an elastic object - when stretched, it exerts a restoring force which tends to bring it back to its original length. This restoring force is generally proportional to the amount of stretch, as described by Hooke's Law. For wires or columns, the elasticity is generally described in terms of the amount of deformation (strain) resulting from a given stress (Young's modulus). Bulk elastic properties of materials describe the response of the materials to changes in pressure. 弹性是物体或材料的一种性质，使它在受到变形后能够恢复到原来的形状。如果物体恢复到原来形状的精度更高，就认为它更弹性。橡皮筋容易被拉伸，一旦释放就会几乎恢复到原来的长度，但它的弹性不如钢琴弦。钢琴弦更难被拉伸，但因为其恢复到原长的精度更高，所以被认为比橡皮筋更弹性。真正的钢琴弦可以被敲击数百次而不会拉伸得足够明显以至于音调明显偏离。弹簧是一个弹性物体的例子——当被拉伸时，它会施加一个恢复力，试图将其恢复到原来的长度。这个恢复力通常与拉伸的量成正比，如胡克定律所述。对于 wires 或 columns，弹性通常用给定应力（杨氏模量）所导致的变形（应变）来描述。材料的体积弹性性质描述了材料对压力变化的响应。
|
Index Periodic motion concepts 索引 周期性运动概念 | ||
|
Go Back
返回 |
Hooke's Law胡克定律
One of the properties of elasticity is that it takes about twice as much force to stretch a spring twice as far. That linear dependence of displacement upon stretching force is called Hooke's law.  弹性的一种性质是，要将弹簧拉伸两倍的距离，所需的力量大约是两倍。这种位移与拉伸力之间的线性关系称为胡克定律。 |
Index Periodic motion concepts 索引 周期性运动概念 | ||
|
Go Back
返回 |