56 lines
1.7 KiB
Markdown
56 lines
1.7 KiB
Markdown
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---
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id: 5900f3fc1000cf542c50ff0f
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challengeType: 5
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videoUrl: ''
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localeTitle: 问题144：研究激光束的多次反射
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---
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## Description
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<section id="description">在激光物理学中，“白色单元”是镜像系统，其充当激光束的延迟线。光束进入细胞，在镜子上反弹，最终恢复原状。我们将考虑的特定白色单元是椭圆形，其等式为4x2 + y2 = 100。顶部对应于-0.01≤x≤+ 0.01的部分缺失，允许光线通过孔进入和退出。 <p>此问题中的光束从白色单元外部的点（0.0,10.1）开始，光束首先在（1.4，-9.6）处撞击镜子。每次激光束撞击椭圆的表面时，它遵循通常的反射定律“入射角等于反射角”。也就是说，入射光束和反射光束都与入射点处的法线形成相同的角度。在左图中，红线表示激光束与白色单元壁之间的前两个接触点;蓝线表示在第一次反弹入射点处与椭圆相切的直线。给定椭圆的任意点（x，y）处的切线的斜率m为：m = -4x / y法线为垂直于入射点处的该切线。右侧的动画显示了光束的前10个反射。 </p><p>在离开之前，光束到达白细胞内表面的次数是多少？ </p></section>
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## Instructions
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<section id="instructions">
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</section>
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## Tests
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<section id='tests'>
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```yml
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tests:
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- text: <code>euler144()</code>应返回354。
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testString: assert.strictEqual(euler144(), 354);
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```
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</section>
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## Challenge Seed
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<section id='challengeSeed'>
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<div id='js-seed'>
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```js
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function euler144() {
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// Good luck!
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return true;
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}
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euler144();
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```
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</div>
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</section>
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## Solution
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<section id='solution'>
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```js
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// solution required
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```
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/section>
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