Energy and Motion能量與運動
Energy is the ability to do work or cause change.
能量就是「做功」或「讓東西產生改變」的能力。
Moving things have energy. A fast ball has more energy than a slow ball. When things bump, energy moves from one to the other. 會動的東西有能量。跑得快的球比跑得慢的球有更多能量。東西互相碰撞時，能量會從一個傳到另一個。
Tap the speaker to hear the English. Turn off 顯示中文 to practice in English only. 按喇叭可以聽英文發音。把右上角「顯示中文」關掉，可以挑戰只看英文。
Forces Start Motion力讓東西動起來
A force is a push or a pull.
力就是「推」或「拉」。
A force can make an object start moving. Then the object has motion energy.
力可以讓東西開始移動，移動的東西就有了「動能」。
Try it! Is it a push or a pull? 試試看！這是推還是拉？
Energy, Speed, and Moving Objects能量、速度與移動的物體
Question: How are speed and energy related? 速度和能量有什麼關係？
Potential energy is stored energy. A ball at the top of a ramp has potential energy.
位能是「儲存起來」的能量。放在斜坡頂端的球有位能。
Kinetic energy is the energy of motion. When the ball rolls down, potential energy changes into kinetic energy.
動能是「運動」的能量。球滾下來時，位能會變成動能。
Speed is the distance an object moves in a certain amount of time. The faster an object moves, the more energy it has.
速度是物體在一段時間內移動的距離。物體跑得越快，能量就越多。
Try it! Pick a start height and a ball, then let it roll. 試試看！選起點高度和球，然後讓它滾下來。
| Trial次數 | Height高度 | Ball球 | Time in zone通過時間 | Speed速度 | Kinetic energy動能 |
|---|---|---|---|---|---|
| Your results go here. 你的實驗紀錄會出現在這裡。 | |||||
Collisions碰撞
Question: What happens to energy when objects collide? 東西相撞時，能量會怎麼樣？
A collision is when one object bumps into another object.
碰撞就是一個物體撞到另一個物體。
In a collision, energy is transferred from one object to the other. Both objects change speed.
碰撞時，能量會從一個物體「傳遞」到另一個物體，兩個物體的速度都會改變。
Some energy changes into sound and heat. That is why a crash makes a noise.
有一部分能量會變成聲音和熱，所以撞到東西時會發出聲音。
Try it! Roll the ball into the box at different speeds. 試試看！用不同速度讓球撞箱子。
Energy Transfer能量的傳遞
Question: How does energy move from place to place? 能量怎麼從一個地方跑到另一個地方？
Energy can be transferred from place to place by sound, light, heat, and electric currents.
能量可以靠聲音、光、熱和電流，從一個地方傳到另一個地方。
Energy can also be transformed. That means it changes from one kind of energy to another.
能量也可以「轉換」，就是從一種能量變成另一種能量。
Try it! What kind of energy comes out? 試試看！最後跑出來的是哪一種能量？
Topic 1 Words第一單元單字
關掉「顯示中文」時，中文會變模糊，點一下才看得到，可以拿來自我測驗。