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在初中物理(人教版)八年级上册第二章第三节“声的利用”一节中,课本第40页演示实验,如图2.3.5所示,将发声扬声器对准烛焰,播放音乐,你看到了什么现象?这说明了什么问题?这个实验是想说明:声波能够传递能量。好,问题来了:为什么要对准?而且要放近了效果才能显现出来?离远一点,行吗?相信很多老师在课前都做过这个实验,离远了效果不明显或是压根没效果。那能说明声波能够传递能量吗?
In the junior high school physics (PEP) eighth grade on the second chapter third section “use of sound ” section, textbook page 40 demonstration experiment, as shown in Figure 2.3.5, the sound speaker at the candle flame , Playing music, what do you see? What’s the problem? The experiment is trying to show that sound waves are able to deliver energy. Well, the question is: Why align? And to be close to the effect in order to show up? A little further, OK? I believe many teachers have done this experiment before class, the effect is not obvious or not effect. That shows that the sound waves can transfer energy?