設計橋樑/結構與強度 材料: 20根吸管，1m膠帶 橋長: 25cm 除兩端之外不能用橋墩 http://bridgecontest.usma.edu/download.htm 材料: 20根吸管，1m膠帶 橋長: 25cm 除兩端之外不能用橋墩
3 振盪 尼米茲公路上的悲劇 1989 The Loma Prieta Earthquake, 7.1 on the Richter scale, causes the double-decked Nimitz Freeway (I-880) in Oakland, CA, to collapse, killing 67, and damages the Embarcadero Freeway, the San Francisco-Oakland Bay Bridge, and other roads in the Bay Area. The death toll is less than at first expected--although the earthquake occurred during evening rush hour, many residents had gone home early to watch the Oakland A's and the San Francisco Giants in the World Series.
3.1 簡協運動 Simple Harmonic Motion (SHM) Frequency (頻率) [hertz(Hz)] - f Period (週期) - T Periodic/harmonic motion displacement
振幅、週期、相位、角頻率 角頻率 Amplitude, phase, and angular frequency
速度、加速度
3.2 SHM 中的作用力
例一 板子+二逆向轉軸 力平衡方程式
k = 0.40 L = 2.0cm 力矩平衡方程式
3.3 SHM 中的能量
圖示
3.4 An Angular SHM 扭擺
例二由扭擺求轉動慣量
由扭擺求週期
3.5 Pendulum 單擺 The Simple Pendulum
物理擺 單擺
測量g值
例三 圓盤物理擺求週期 h = R/2
例四 企鵝跳水 m = 12kg k = 1300N/m
3.6 SHM 和等速率圓周運動 SHM 是等速率圓周運動在其圓周直徑之投影
有阻滯 S H M Damped (阻尼) 阻滯力 微分方程式
指數衰減
3.7 強迫振盪與共振 自然頻率與外來驅動頻率 共振條件 共振例 Radio and TV tuning 3.7 強迫振盪與共振 自然頻率與外來驅動頻率 共振條件 共振例 Radio and TV tuning The collapse of the Nimitz freeway The Tacoma narrow bridge The bay of Fundy
共振圖示
共振圖示
例五 盪秋千
例六 The Tacoma narrow bridge Howard Clifford
例七 The collapse of the Nimitz freeway
例八 全球最大的潮差 Bay of Fundy the average tide range is 12 metres and can reach 16 metres when the various factors affecting the tides are in phase Earth's mid-ocean tide reaches an average height of 0.51 meters
敬請期待 物理 V–波動
簡協運動的動畫
Simple Harmonic Motion
Harmonic Motion