aaalviny

雖然唔肯定你唔明邊一part, 但我嘗試逐part講:

思考模式: 題目要計depth, 畫圖會好睇d

part 1: 你能唔能夠畫到幅圖出黎? 如下

part 2: 佢潛得唔夠深的話, total internal reflection會令到冇光能夠由水上refract到身處海底既diver
佢越潛越深的話, 就越會望到多水面上既野 (黑 -> 紅 -> 綠)
(能理解 i 與 r 與 total internal reflection之間既關係?)

part 3: critical point如紅筆所示
sin theta = 1/1.33 by Snell's Law

part 4: 計min depth
tan theta = 0.8 / min depth
min depth = 0.7m