动能和势能

The sum of kinetic energy and potential energy doesn´t change.

动能和势能，总和没有改变。

In many example of mechanical motion, there is an interchange between kinetic and potential energies.

在很多机械运动的实例中，有一种是动能和势能之间的相互转化。

The energy app roach (Hamilton´s principle) is employed to obtain the governing partial differential equation of motion from the expressions of potential and kinetic energies of the system.

通过系统的动能和势能表达式，应用哈密尔顿原理，可获得主导偏微分运动方程。

Two types of tidal energy can be extracted: Kinetic energy of currents due the tides and potential energy from the difference in height (or head) between high and low tides.

两种类型的潮汐能可提取：电流，由于潮汐的动能和势能之间的高度，从在涨潮和退潮（或主管）的差异。

The sum of the kinetic and potential energy of the body is called its total mechanical energy.

物体的动能和势能之和称为物体的总机械能。