题目内容
如图所示,在真空中有一等腰直角三棱镜ABC,一束单色光以60°的入射角从AB侧面的中点射入,折射后再从AC侧面射出,出射光线偏离入射光线的角度为30°。已知AB =" AC" = d,单色光在真空中的光速为c。
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/201408241402099191572.png)
(1)请作出光路图;(2)求单色光通过三棱镜的时间t。
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/201408241402099191572.png)
(1)请作出光路图;(2)求单色光通过三棱镜的时间t。
(1)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/201408241402100902759.png)
(2)![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824140210324612.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/201408241402100902759.png)
(2)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824140210324612.png)
(1)如图所示 (1分)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/201408241402100902759.png)
(2)α + β = ∠A = 90°,θ = (i– α) + (r– β)
得 r = ∠A + θ– i = 60°, (2分)
而
= n,
= n,i =" r" = 60° (2分)
得 α =" β" = 45°,n =
(2分)
t =
,s =
d,n =
(2分)
得 t =
=
(1分)
本题考查光的折射,光的折射规律画图,然后根据几何知识可得入射角,代入折射定律,求出折射率和真空射入玻璃的折射角与从玻璃射入真空的入射角,根据几何知识可得光在玻璃中的位移,以及根据公式n =
求出的速度,即可求出传播时间。
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/201408241402100902759.png)
(2)α + β = ∠A = 90°,θ = (i– α) + (r– β)
得 r = ∠A + θ– i = 60°, (2分)
而
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824140210543537.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824140210589583.png)
得 α =" β" = 45°,n =
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824140210636477.png)
t =
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824140210667345.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824140210714413.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824140210761346.png)
得 t =
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824140210792604.png)
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824140210324612.png)
本题考查光的折射,光的折射规律画图,然后根据几何知识可得入射角,代入折射定律,求出折射率和真空射入玻璃的折射角与从玻璃射入真空的入射角,根据几何知识可得光在玻璃中的位移,以及根据公式n =
![](http://thumb.1010pic.com/pic2/upload/papers/20140824/20140824140210761346.png)
![](http://thumb2018.1010pic.com/images/loading.gif)
练习册系列答案
相关题目