[考古] 台聯95

[vvvv9999 (龍方大隊長)]

An object is placed in front of a convex mirror at the distance at the

distance of 30.0 cm.Find the distance between the image abd the mirror and

the lateral magnification if the focal distance of the mirror is 20.0cm

(a)12 cm and +0.4 (b)12 cm and -0.4 (c)60cm and +2.0 (d)60cm and -2.0

(e)15 cm and +0.5

第一個應該是算q 1/30+1/q=1/20 q=60

請問第二個是要算什麼呢@@


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推 dycc:放大倍率 M=-q/p
→ vvvv9999:感謝..所以答案是d?
→ dycc:應該是:| 可是我記得高中的時候放大率的定義是M=q/p
→ dycc:可是benson上有多一個負號 所以我覺得應該是d :p
推 baseketed:我覺得是c耶,因為是像正立的阿
→ dycc:像是倒立的啊 剛剛翻書了 Benson寫說放大率的負號代表倒立的
→ dycc:像
推 baseketed:題目是凸面鏡沒錯吧?那應該是正立縮小虛像阿...
→ dycc:對耶 我以為是凸透鏡 對不起我笨了orz
→ baseketed:我畫圖發現成像位置會在焦點跟面鏡之間欸...但是q>f..
→ baseketed:有人能幫我解答嗎
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作者: baseketed (巧哥) 看板: TransPhys
標題: Re: [考古] 台聯95
時間: Tue Jul  7 21:51:05 2009

※ 引述《vvvv9999 (龍方大隊長)》之銘言：
: An object is placed in front of a convex mirror at the distance at the
: distance of 30.0 cm.Find the distance between the image abd the mirror and
: the lateral magnification if the focal distance of the mirror is 20.0cm
: (a)12 cm and +0.4 (b)12 cm and -0.4 (c)60cm and +2.0 (d)60cm and -2.0
: (e)15 cm and +0.5
: 第一個應該是算q 1/30+1/q=1/20 q=60
: 請問第二個是要算什麼呢@@


答案應該是a

凸面鏡的f要代負的

所以可求得q=-12(因為是虛像)

M=-q/p=h'/h=+0.4






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