本區搜索:
Yahoo!字典
打印

[問題] F.3 Physics Uniform Quiz Questions

[隱藏]

F.3 Physics Uniform Quiz Questions

(How to calculate?)


A diver is directly under a large patch of dirty oil floating on the water surface. The oil blocks all the light falling on it. Assume the oil patch is circular in shape and has a radius of 0.8 m. Find the minimum depth of the diver so that he can see objects above the water surface.
(Given: the refractive index of water = 1.33)

A. 0.7 m
B. 0.9 m
C. 1.1 m
D. 1.4 m
   

TOP

Phy Question

(How to calculate?)


A diver is directly under a large patch of dirty oil floating on the water surface. The oil blocks all the light falling on it. Assume the oil patch is circular in shape and has a radius of 0.8 m. Find the minimum depth of the diver so that he can see objects above the water surface.
(Given: the refractive index of water = 1.33)

A. 0.7 m
B. 0.9 m
C. 1.1 m

TOP

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

TOP

引用:
原帖由 Hin2000 於 2015-6-5 03:44 PM 發表
(How to calculate?)


A diver is directly under a large patch of dirty oil floating on the water surface. The oil blocks all the light falling on it. Assume the oil patch is circular in shape and h ...


1. Total Internal Reflection!


2. Draw a right-angled triangle as shown in the figure


3. By General Snell's Law: (1.33) sinC = (1) sin(90) => C = 48.75


4. Tan(48.75) = 0.8 / d => d = 0.7 m


Do you understand why I have to draw the diagram as shown and do in this way?
附件: 您所在的用戶組無法下載或查看附件
我係黎sir, 香港中學文憑試數學, 物理及經濟奪取5**, 16年補習經驗
導師簡介:按此進入

TOP

thx  

TOP

我見到上面有人賣廣告呀~

TOP

重要聲明:小卒資訊論壇 是一個公開的學術交流及分享平台。 論壇內所有檔案及內容 都只可作學術交流之用,絕不能用商業用途。 所有會員均須對自己所發表的言論而引起的法律責任負責(包括上傳檔案或連結), 本壇並不擔保該等資料之準確性及可靠性,且概不會就因有關資料之任何不確或遺漏而引致之任何損失或 損害承擔任何責任(不論是否與侵權行為、訂立契約或其他方面有關 ) 。