Wave Motion I :Reflection of L

2011-03-29 5:09 am

1.以下哪項是發光體?
(1)蠟燭的火焰
(2)太陽
(3)月亮
A. 只有 (1) 和 (2)
B. 只有 (1) 和 (3)
C. 只有 (2) 和 (3)
D. (1)、(2) 和 (3)
2.光線射向平面鏡,入射線和反射線之間的夾角為 40°。反射角是多少?


A. 20°
B. 40°
C. 50°
D. 70°
3.如下圖所示,有兩塊相互垂直的平面鏡,光束射向其中一塊平面鏡。求 θ。

圖片參考:http://npaw2.learnmore.com.hk/OUP/Npaw2/Paper/0909/images/3A01/3A0106.jpg


A. 30°
B. 70°
C. 120°
D. 150°
更新1:

that's Reflection of Light...sor

更新2:

how about this: 物體放在距離凸透鏡 25 cm 的地方,在距離透鏡 18 cm 的屏幕上形成清晰的像。凸透鏡的焦距是多少? A. 64.3 cm B. 43.0 cm C. 27.7 cm D. 10.5 cm 如下圖所示,物體放在凸透鏡前方。形成的是實像還是虛像?像距是多少? http://npaw2.learnmore.com.hk/OUP/Npaw2/Paper/0911b/images/ch A. 像距為 17.1 cm 的實像 B. 像距為 17.1 cm 的虛像 C. 像距為 7.06 cm 的實像 D. 像距為 7.06 cm 的虛像

回答 (1)

2011-03-29 5:20 am
✔ 最佳答案
1. The answer is option A.The moon only reflects light from the sun.
2. Since incident angle = reflection angle.hence, reflection angle = 40/2 degrees = 20 degreesThe answer is option A
3. After the first reflection, the light ray makes an angle of 20 degrees with the mirror surface (Law of Reflection).

During the second reflection, the light ray makes an angle of (90-20) degrees = 70 degrees with the mirror surface.

Hence, angle (theta) = 70 degrees after reflection.
The answer is option B


收錄日期: 2021-04-24 10:37:41
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20110328000051KK01346

檢視 Wayback Machine 備份