题目内容
如图所示实线是某时刻的波形图像,虚线是经过0.2s时的波形图像。求:
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/201408250034125874328.jpg)
(1)波传播的可能距离;
(2)可能的周期(频率);
(3)可能的波速;
(4)若波速是35m/s,求波的传播方向;
(5)若0.2s小于一个周期时,求传播的距离、周期(频率)、波速。
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/201408250034125874328.jpg)
(1)波传播的可能距离;
(2)可能的周期(频率);
(3)可能的波速;
(4)若波速是35m/s,求波的传播方向;
(5)若0.2s小于一个周期时,求传播的距离、周期(频率)、波速。
见解析
(1)波的传播方向有两种可能:向左传播或向右传播。
向左传播时,传播的距离为
。
向右传播时,传播的距离为
。
(2)向左传播时,传播的时间为
。得
。
向右传播时,传播的时间为
。得
。
(3)计算波速有两种方法:
或
。
向左传播时,
m/s,
或
m/s![](http://thumb.1010pic.com/pic2/upload/papers/20140825/20140825003412790645.png)
向右传播时,
m/s,
或
m/s.![](http://thumb.1010pic.com/pic2/upload/papers/20140825/20140825003412790645.png)
(4)若波速是35m/s,则波在0.2s内传播的距离为
,所以波向左传播。
(5)若0.2s小于一个周期,说明波在0.2s内传播的距离小于一个波长.则:向左传播时,传播的距离
m;传播的时间
得:周期
=0.267s;波速
=15m/s。向右传播时,传播的距离
m;传播的时间
得:周期
=0.8s;波速
=5m/s。
向左传播时,传播的距离为
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/201408250034126021273.png)
向右传播时,传播的距离为
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/201408250034126181219.png)
(2)向左传播时,传播的时间为
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/20140825003412634654.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/201408250034126491366.png)
向右传播时,传播的时间为
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/20140825003412665609.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/201408250034126801326.png)
(3)计算波速有两种方法:
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/20140825003412712472.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/20140825003412727528.png)
向左传播时,
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/201408250034127431125.png)
或
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/201408250034127741265.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/20140825003412790645.png)
向右传播时,
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/201408250034129301075.png)
或
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/201408250034129461247.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/20140825003412790645.png)
(4)若波速是35m/s,则波在0.2s内传播的距离为
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/201408250034129921155.png)
(5)若0.2s小于一个周期,说明波在0.2s内传播的距离小于一个波长.则:向左传播时,传播的距离
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/20140825003413008621.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/20140825003413024533.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/20140825003413055304.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/20140825003413070265.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/20140825003413086559.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/20140825003413117475.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/20140825003413055304.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140825/20140825003413070265.png)
![](http://thumb2018.1010pic.com/images/loading.gif)
练习册系列答案
相关题目