冷风1985

少女时代12 发表于 2-11-2011 18:48
Question 5A 可以用 8cm 吗 ？ 虽然是给了7cm可是我用了8cm。。。
还有 11 （ii）可以说因为 optical fibre ...

5A if you used 8cm, you would get a wrong value of net force. So you can only get 4 marks.

11(ii) you will get 2 marks. you didn't state that light travels in optically denser medium, and incident angle is greater than critical angle.

a2590194

tianya1 发表于 2-11-2011 17:46
扣了5分了   

section B  没写完呀、

phy 65 chem 65 mcq 40 partical 30 total 200

344508665

Qn5的drawing vector diagram 另外两条线必须用虚线吗？可以用实线吗？我量出来的长度是12厘米耶？我量错了？！
Qn7(a)可以写move further away from the lens吗？
Qn11(b)(i)可以写Both travel at the speed of 3.0X10的8次方吗？in vacuum

tianya1

嗯，谢谢楼上了

a2590194

一共大概是扣了111-13分 因为这种explain的 题要看你怎么解释，还不错了 老师知道去年combine science A1是多少吗 还是75？没变？  

冷风1985

qh94 发表于 2-11-2011 18:18
老师 for qn 5a 可以用 tip to tail method?

cannot, the question asked you to use lines given. In other words, he want you to used parallelogram rule instead of trianglar rule

tianya1

12 a
the force exerts by foot should be greater than the piston since it has a shorter perpendicular distance than the piston

冷风1985

a2590194 发表于 2-11-2011 19:07
一共大概是扣了111-13分 因为这种explain的 题要看你怎么解释，还不错了 老师知道去年combine science A1是 ...

not very sure.

a2590194

冷风1985 发表于 2-11-2011 17:24
应该是 to the right

老师你发的e mail 里没有e math p1的原题呀

kyukyung

angziru 发表于 2-11-2011 18:04
For question 7(a), i wrote that the moveable screen will move backward. Is it correct to say so?

same! i also said it will move backwards, away from the lens