[DSE Physics] Interference 干涉

[@ivanlam802]

動畫好有心機！睇完Ｄ片就好清楚呢個ＴＯＰＩＣ講緊乜野同埋背後原理，多謝晒

[@allisonchu8251]

瞓唔住，睇marc yam

[@saltamsal2711]

有種相逢恨晚既感覺 :( 今年係咪唔會出radioactivity啊..因為呢課比較易學又短

[@MarcYam]

今年唔會出到radioactivity了，呢課比較淺嘛

[@charlesli5546]

Hi. Will you upload the topics of light? I am sick of the diffraction grating those concepts 🙏🏼

[@MarcYam]

Charles Li yep! I will. But it may take a long time to be uploaded.

[@youknowwho8925]

2：30撥到好攰

[@hi9604]

我想問下當程差係n+0.5λ，當每一點既amplitude 變0，啲energy 去咗邊

[@badboy0575]

5:26 個三角形點解

[@MarcYam]

path difference既symbol。

[@badboy0575]

程差一定用三角形代表？三角形唔係講緊個改變？即例如三角形p係指緊change in momentum咁

[@oil-qw5sm]

I think it should be "Principle of superposition" rather than "Principal of superposition".

[@MarcYam]

oil1155 12345 Thanks for correcting me😂

[@crosbybrownnewbold466]

1:30 點解不是must而有機會

[@MarcYam]

謝謝你，呢度係我表達得唔夠好，我想講既係it is possible，而唔係it may

[@constance4867]

點解兩個coherent 既source 會會變stationary wave 而係destructive interference咗？

[@MarcYam]

因為喺兩個sources之間既直線上，其實每點既path difference都唔一樣，所以有啲位會成為constructive interference，有啲位係destructive interference，所以就會形成stationary wave。

[@constance4867]

@@MarcYam 都係唔係好明，點解兩個wave 重疊咗，stationary wave 都無 superposition 然後加大個or 消失，反而見到晒兩個wave ?😅😅🙇‍♀️

[@MarcYam]

只係透過文字，其實都幾難表達同理解，我再嘗一下。 1. 兩個wave 重疊咗，係有superposition呀(superposition就有重疊既意思)，正正因為兩個wave superpose埋一齊，所以形成stationary wave。 2. 喺stationary wave既node其實就係兩個wave superpose埋一齊之後消失咗，而antinode就係兩個wave superpose埋一齊加大咗。 3. 唔明咩叫做「見到晒兩個wave」??

[@constance4867]

@@MarcYam 我明啦！真係唔該曬🙇‍♀️😅我一開頭話見到兩個waves 係因為我以為郁太快嗰個視覺效果係兩個waves

[@badboy0575]

4:13點解呢度係指咁長

[@MarcYam]

唔明你個問題。

[@badboy0575]

nothing la thx

[@samlam8072]

臨考前問下，如果程差唔係n個lamda或n+0.5個lamda，而可能係1.7/1.2個lamda甘，係相長干涉定係相消干涉

[@MarcYam]

兩者都唔係

[@samlam8072]

@@MarcYam 😂😂甘神奇❗❓

[@badboy0575]

咁想問下逢親wave係咪一定會同時有relection refraction diffraction and interference 咁咪好亂 咁科學家點研究 加上其實wave遇到唔同media or撞到唔同嘢嘅時候 咁咪每個sisutatiom都唔同 即其實physics係一個地球 但人類嘅認知係咪得香港咁大

[@MarcYam]

我鍾意呢句「其實physics係一個地球 但人類嘅認知係咪得香港咁大」。 係呀，所以wave遇到唔同既嘢，個情況都可以好唔同同好複雜，通常科學家會用電腦模擬既方法去睇個wave會發生乜事。

[@badboy0575]

ok thx

[@badboy0575]

3:12 個sources係指咩

[@MarcYam]

隻手。

[@laipo1175]

睇黎考dse前都睇唔到電學全部..

[@MarcYam]

lai po Sorry ar，會盡力而為，雖然我都覺得出唔到全部電

[@laipo1175]

加油！仍然十分感謝你！

[@nathanyip2826]

好奇一問 destructive interference嘅時候個水面係calm 啲particles唔郁咁啲energy去左邊?

[@MarcYam]

去咗constructive interference嗰度，我而家show俾你睇只係一條線上面既particles，但係真實情況唔會係得一條線，而會係一個面，所以有destructive interference就一定有constructive interference呀喇。

[@badboy0575]

何為一個面呢

[@漫-p7l]

其實咩係撥水，個腦諗唔到個畫面...

[@MarcYam]

好似呢個畫面咁：kzbin.info/www/bejne/Y57Ch3d7YqeGncU

[@漫-p7l]

@@MarcYam 多謝解答，但 鴛鴦戲水又係點做到 😅😅

[@samkk857jj4]

But my teacher said destructive interference is (m-0.5)入 otherwise we can't find the correct order

[@MarcYam]

Sam kk857jj it is just a different kind of expression

[@badboy0575]

咁如果唔同frequency嘅wave撞埋一齊會點？

[@MarcYam]

咁個interference pattern就唔會穩定，而係會shift既。

[@badboy0575]

唔係應該都會有番個穩定嘅pattern？始終wave唔會改變frequency 最多個樣唔靚仔

[@loveby21314]

Halooo請問可吾可以出ch1 heat嘅片呀🙈

[@MarcYam]

Yuen Ting Ng 會出heat，已經寫左幾篇heat嘅稿呀嗽，但而家仲做緊wave嘅片，黎緊應該都會出左Wave 同EM先，heat就要再等多等了。

[@loveby21314]

吾該哂🙏🙏

[@kkyt_9154]

Dse heat 係所有課題入而最易

[@user-wz7fn2pq5m]

話說animation係用flash定powerpoint整 好勁

[@MarcYam]

Fu Ting Hin Bryan PowerPoint

[@user-wz7fn2pq5m]

Marc Yam 哇咁一定整左好耐...👏👏

[@MarcYam]

Fu Ting Hin Bryan 無計，電腦白痴，只係識用啲簡單嘅software

[@user-wz7fn2pq5m]

Marc Yam 加油繼續整呀 :)

[@ivanchoi4290]

阿sir 可5 可以考慮出左電學先，你d 片真系好有用:-)

[@garo5442]

我都希望出左電學,電學先真系好難

[@tinyeung3468]

會唔會拍條片講double slit experiment 啊？

[@MarcYam]

Tin Yeung 會呀

[@tinyeung3468]

Marc Yam 正

[@EzyGaming]

5係Lambda咩😂

[@MarcYam]

Ezy傳說聯盟 查過，應該both 都ok