Energy Changes in a Closed System

Energy changes in a closed system follow a conservation law in physics. A conserved quantity is not the same as the everyday use of the word "conserved." In science, a conserved quantity stays constant, or it changes by a definite amount that is transferred to another system and converted into another form of the s...

能量守恒定律指出，孤立系统的总能量始终保持不变。这意味着能量只能从一种形式转化为另一种形式。

例如，位于悬崖顶部的水所储存的势能在下落过程中会转化为动能。

同样，当一块木头燃烧时，储存在木头中的势能会以光和热的形式转化为动能。

从数学上讲，能量守恒定律表示为动能、势能和内能的变化量之和等于零。换句话说，如果一种形式的能量减少，则其他形式的能量会相应增加以作补偿。