Some clever algebra can rearrange this expression to become the average velocity times m times the CHANGE in velocity.

平均速度·m(质量)·速度改变量不过 速度随时间的改变量就是加速度。

In that case, we use the average velocity of each of the particles.

在那种情况下，我们使用每个粒子的平均速度。

And two, that average velocity is equal to distance over time

其次，平均速度等于 随着时间的推移距离。

Knowing this, we can say that power is the net force applied to something with a particular average velocity.

知道了这一点，我们可以说能力是 施加在中等速度物体上的合力。

If you moved the box 5 meters in 2 seconds, then its average velocity was 2.5 meters per second.

如果你在两秒内将盒子移动五米， 它的平均速度是每秒2。5米。

So we can use that to write the equation for average velocity: It’s just delta x over delta t.

所以我们可以用它来写平均速度的方程式：它只是 delta x over delta t。

To get the average kinetic energy, we didn't just take the average velocity and square it.

为了找到平均动能，我们不仅取 正常速度，我们将其平方。

That's average velocity equaling to velocity at time 0 plus the product of acceleration times time.

这个速度的速率等于时间 0 中的速度 加上加速时间的乘积。

But let’s say you wanted to know your average velocity for a certain period -- say, for those first three seconds.

但是假设您想知道某个时间段内的平均速度——比如前三秒。

The square root of the average squared velocity is what we call the root mean square speed.

速率平方的平方根 就是我们所说的均方根速度。

So we can use that to write the equation for average velocity: It's just delta x over delta t.

所以我们用它来写方程 对于平均速度：即 delta x 高于 delta t。

But let's say you wanted to know your average velocity for a certain period -- say, for those first three seconds.

但是假设你想知道你的平均速度 在某个时期… … 比如说，在前 3 秒内。

Marinov's experiment also involves reflecting the light back, and demonstrates that its velocity is different in one direction to the other direction (although the average velocity equates with Einstein).

马里诺夫的实验还涉及将光反射回来，并证明其速度在一个方向与另一个方向不同（尽管平均速度与爱因斯坦相同）。

The equation we use to describe average acceleration is a lot like the one for average velocity, because it’s just the change in velocity divided by the change in time.

我们用来描述平均加速度的方程很像平均速度的方程，因为它只是速度变化除以时间变化。

And the average kinetic energy of the ideal gas molecules in a container, is equal to half of a molecule's mass x the average squared velocity of the molecules.

它的速度的平方… … 和分子的平均动能 容器中的理想气体等于分子质量的一半。

The net velocity of a gas in any one direction will always be lower than the average velocity of its molecules because the overall motion of the gas is hindered by collisions among the individual particles.

气体在任何一个方向上的净速度总是低于其分子的平均速度，因为气体的整体运动受到单个粒子之间碰撞的阻碍。

If you listened carefully, you learned the difference between the net velocity of a gas and the average velocity of its particles, and that both things have a lot to do with the mass and kinetic energy of the particles.

如果你仔细听，你就会了解到气体的净速度与其粒子的平均速度之间的差异， 并且这两者都与粒子的质量和动能有很大关系。