节能

 

What can an amusement park ride tell us about energy?
::游乐园骑车能告诉我们什么能源?

This  platform  is about to change  energy  from potential to kinetic. The energy is not lost; it just changes forms. The platform is on top of a precipice. The rest of the ride runs on the  potential energy  the platform has when it is at the top.
::这个平台即将将能量从潜能变为动能。 能量不会丢失, 它只是改变形式。 平台位于悬崖顶端。 其余的运行时间运行在平台顶端时的潜在能量上 。

Conservation of Energy
::保护能源

In this section, we're not talking about saving energy. This section is about how energy cannot be created or destroyed. Energy can only change forms. So we say that energy is conserved. Energy changes form when something happens. But the total amount of energy always stays the same. The  Law of Conservation of Energy  says that energy cannot be created or destroyed. Scientists observed that energy could change from one form to another. They also observed that the overall amount of energy did not change.
::本节中,我们不是在谈论节能。本节是关于能源如何不能创造或破坏。能源只能改变形式。因此,我们说能源是节能的。当发生某种事情时,能源会变化。但能源总量总是保持不变。《节能法》指出能源不能创造或破坏。科学家们认为能源可以从一种形式改变为另一种形式。他们也指出能源总量没有变化。

Energy Changes
::能源变化

Here is an example of how energy changes form: kicking a soccer ball. Your body gets energy from food. Where does the food get its energy? If you're eating a plant, then the energy comes directly from the  . If you're eating an animal, then the energy comes from a plant that got its energy from the Sun.
::这里的例子说明了能源变化的形式:踢足球。你的身体从食物中获取能量。食物从哪里获得能量?如果你在吃植物,那么能量就直接来自植物。如果你在吃动物,那么能量就来自从太阳中获取能量的植物。

Your body breaks down the food. It converts the food to  chemical energy  and stores it. When you are about to kick the ball, the energy must be changed again.  Potential energy  has the potential to do work. When your leg is poised to kick the ball but is not yet moving, your leg has potential energy. A ball at the top of a  hill  has the potential energy of  .
::你的身体打破了食物。 它把食物转换成化学能量, 并储存它。 当你即将踢球时, 能量必须再次改变。 潜在的能量有工作潜力。 当你的腿准备踢球, 但是还没有动起来时, 你的腿有潜在的能量。 在山顶的球有潜在的能量 。

Kinetic energy  is the energy of anything in motion. Your muscles move your leg, your foot kicks the ball, and the ball gains kinetic energy ( Figure   ). The kinetic energy was converted from potential energy that was in your leg before the kick. The action of kicking the ball is energy changing forms. The same is true for anything that involves change.
::动能是运动中任何东西的能量。你的肌肉动动你的腿,你的脚踢球,球能增动能量(图 ) 。动能是从脚踢前腿部的潜在能量转换而来的。踢球的动作是能量变化的形式。任何涉及变化的事物都是如此。

 

Summary
::摘要

• Energy cannot be created or destroyed. This is the Law of Conservation of Energy.
  ::不能创造或摧毁能源,这是《能源保护法》。

• Energy changes from one form to another.
  ::从一种形式到另一种形式的能源变化。

• Some types of energy are chemical, kinetic, and potential.
  ::某些类型的能源是化学、动能和潜力。

Review
 ::回顾

1. Compare and contrast potential energy and kinetic energy.
   ::比较和对比潜在的能量和动能。

1. What does it mean to say that energy cannot be created or destroyed.
   ::说不能创造或摧毁能源意味着什么。

1. Think about riding a bike up and down a hill. Where does energy change form in each step of the process and what type is each?
   ::想想骑自行车上下山坡。在这一过程的每一步中,能源变化在哪里? 每种变化的类型是什么?

Explore More
::探索更多

Use the resource below to answer the questions that follow.
::利用以下资源回答以下问题。

1. What types of energy is released when a light bulb is turned on?
   ::当灯泡被打开时释放出何种能源?

1. What types of energy are involved in a baseball being hit by a bat?
   ::棒球被蝙蝠击中涉及何种能量?

1. What types of energy are involved in releasing an arrow from a bow?
   ::从弓中释放箭头涉及何种能源?

1. What types of energy involved in making electricity?
   ::电力生产涉及何种能源?