有冇DSE Physics嘅巴打

但係外國都係High school偏淺，要深既入到U先開始深
係大陸人唔理乜9都要深左先

consider the bullet and the door together to be a system, the only external force to the system at the instant just after the collision is the force acting on the hinge, which contribute 0 torque around it since the separation vector between the force and the reference point is just the zero vector

拜仁份Abitur有special relativity cls

歐洲嘅syllabus其實唔淺，不過佢地出問題冇咁刁鑽，基本上你明白大概發生緊咩事就會答到

而香港嘅試卷問題比較麻煩，好似DSE數學啲3D-geom咁冇乜新concept但你要有skills先做到，所以高分嘅人多數都只係因為勤力操卷(當然有少部分人係堅揪裸考都5**)，而唔係真係叻
然後呢啲以為自己好叻嘅人入到U就炒曬車

美國high school就真係淺，不過美國中小學教育公認係垃圾，甚至公立大學嘅學生普遍都係好撚廢，我見過有理工科學生寫得出 cos x/x = cos
多數精英都係讀私立學校，而佢地又同唔少名牌大學有合作，所以呢班人中學就已經見多識廣，唔會淨係識syllabus入面嘅嘢

好撚同意

子彈都喺個system入面

High energy唔係CU先多咩

所以咪後悔囉

巴打諗住行research定做教畜

呢度嘅巴打真係好勤力
雖然有好多content係唔關DSE事

幅牆會有個reaction force

唔勤力哪來offer
利申 GRE都未考嘅廢渣

啱聽

而家日日mon住工程屍post都係得個驚字

想入CU CS，如果入到去仲有排捱

我諗係要視乎個system嘅symmetry係咪preserve
Noether's theorem 應該回答到呢個問題