The equivalent resistance of a parallel circuit
can be determined by
.
A similar-looking formula found in a basic mathematics question involving parallel lines as shown below:
The equivalent resistance of a parallel circuit
can be determined by
.
A similar-looking formula found in a basic mathematics question involving parallel lines as shown below:
1.緣起
某次中三共同備課堂,同事甲提出證明錐體體積的方法,如下:
考慮一個鈄截正三角柱體(truncated right triangular prism),即三條側棱皆與底垂直者:
設側棱長度分別為 。因其體積是底面積 A 乘以「平均高度」,即鈄截正三角柱體的體積為
於是對於錐體,其底面積為 A,高為 h 者,
只要代入 ;,便知其體積是
利用 Miuria fold,做出很薄的鋰離子電池,加大電池能量密度。
資料來源:
More at
“Physicists from CERN team up with TED-Ed to create five lessons that make particle physics child’s play"
剛看「一日一通識」顏冊群組,見
『六十年代,物理學家已經提出「希格斯場」理論。直至去年,全球最大的基礎科研機構CERN公布可能找到被稱為「上帝粒子」的希格斯粒子。「上帝粒子」的發現對物理學研究有何意義?「希格斯場」又怎去理解?』
詳見:
http://utalks.etvonline.tv/article13.php
也貼些 (more…)
JUN 2012
拉米示·拉斯卡展現了飛秒成像,一種在萬分之一秒中成像的新型成像技術,所以它展示了光的運動。這個技術有可能被用來看到拐角處的東西,或者在不用X光機的情況下透視身體。
Photography is about creating images by recording light. At the MIT media lab, professor Ramesh Raskar and his team members have invented a camera that can photograph light itself as it moves at, well, the speed of light.