凹面鏡的特性
回答 (3)
2012-09-17 4:23 am
✔ 最佳答案
凹面鏡有聚焦作用，並假定其焦點在球心或球心與球面之間，而且凹面鏡對準太陽時也能起火，使棉絨燃著。此後阿基米德對此也有所研究。傳說當羅馬人包圍敘拉古時，阿基米德發明了用凹面鏡專門點火的裝置，當敵人到達距離城牆一個箭程時，用這種鏡子使敵人的船隊起火，燒毀了國古人很早就認識到了凹面鏡的聚焦特性，並利用其向日取火。 
2012-09-15 5:02 pm
你要我用中文定用英文寫呀
2012-09-13 6:18 pm
The following web-page gives a very good dscription on the images formed by a concave mirror,
http://www.physicsclassroom.com/class/refln/u13l3e.cfm
It explains how the relative location, orientation (upright or inverted), size(magnified, reduced, or of the same size as the object), and type of image (real or virtual) vary under five different situations.
http://www.physicsclassroom.com/class/refln/u13l3e.cfm
It explains how the relative location, orientation (upright or inverted), size(magnified, reduced, or of the same size as the object), and type of image (real or virtual) vary under five different situations.
收錄日期: 2021-04-13 18:58:21
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20120912000051KK00542