初中物理概念
光、电、热、力
1．一切正在发声的物体都在振动，如果振动停止，那么发声停止。
2．声音靠介质传播，在15℃空气中的传播速度是340m/s，真空不能传声。
3．声音的三要素是：①音调（是指声音的高低，它是由发声体振动的频率决定的，频率越大，音调越高）。②响度（是指声音的大小，它跟发声体振动的振幅有关，还跟距发声体的远近有关，振幅越大,距发声体越近，响度越大）。③音色（指不同发声体声音特色,不同发声体在音调和响度相同的情况下,音色是不同的。）
| 熱門國家 | 系統支援 | 版本 | 費用 | APP評分 | 上架日期 | 更新日期 |
|---|---|---|---|---|---|---|
| 中國 China | Android Google Play | 1.8 App下載 | 免費 | 2014-05-10 | 2015-03-21 |
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