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生活中许多金属类和非金属类物体,当受到外力的作用或气温变化的影响,都会产生延伸性。如吊车上用的钢丝绳,在经过无数次的起吊重物之后,长度逐渐延长,其初始的抗拉强度渐渐降低,一旦接近或超过其设计的最大拉力值,便从薄弱部分折断;火车的钢轨会随着气温的升高而延伸。钓鱼用的尼龙线,当受到外力作用时,同样具有延伸性,只是由于品牌不同,质量有别,所产生的延伸程度不同。
Many metallic and nonmetallic objects in life have extensibility when subjected to the effects of external forces or temperature changes. For example, a cable used for a crane has a length that gradually increases after an infinite number of lifting loads, its initial tensile strength gradually decreases, and once it approaches or exceeds its designed maximum tension value, it breaks off from a weak part; the rail of the train Will extend as the temperature rises. Fishing nylon line, when subjected to external forces, the same extensibility, but because of different brands, different quality, resulting in different degrees of extension.