# Chapter 2 Motion Along a Straight Line 2

• Slides: 28

Chapter 2 Motion Along a Straight Line 第 2章 直線運動

Chapter 2 Straight Line Motion 2 -1 What is Physics? 2 -2 Motion 2 -3 Position and Displacement 2 -4 Average Velocity and Average Speed 2 -5 Instantaneous Velocity and Speed 2 -6 Acceleration 2 -7 Constant Acceleration: A Special Case 2 -8 Another Look at Constant Acceleration 2 -9 Free-Fall Acceleration 2 -10 Graphical Integration in Motion Analysis

2 -1 What is Physics? • NASCAR – National Association for Stock Car Auto Racing • tectonic plate 地殼板塊 • artery 動脈 • one-dimensional motion 一維運動

2 -2 Motion 運動 • • kinematics 運動學 particle 質點；粒子 stiff pig stiff 剛性 pig 生鐵、銑鐵 playground slide 遊戲場滑梯 tumbleweed 風滾草

2 -3 Position and Displacement • • • reference point 參考點、基準點 origin 原點 (zero point 零點) position 位置 displacement 位移 x = x 2 x 1 distance 距離 vector quantity 向量 (vector) – magnitude 量值 (absolute value 絕對值) – direction 方向

Position

2 -4 Average Velocity and Average Speed • • • armadillo 犰狳 average velocity 平均速度 vavg slope 斜率 average speed 平均速率 savg acceleration 加速度

Graph of x(t)

Graph of x(t)

Average Velocity

Sample Problem

2 -5 Instantaneous Velocity and Speed • instantaneous velocity 瞬時速度 v • velocity 速度 v • speed 速率 – Speed is the magnitude of velocity • speedometer 速率計

Sample Problem

2 -6 acceleration 加速度 • average acceleration 平均加速度 aavg • instantaneous acceleration 瞬時加速度 a • acceleration 加速度 a

2 -7 Constant Acceleration: Special Case A

Equations for Motion with Constant Acceleration

Equations for Motion with Constant Acceleration

Sample Problem

2 -8 Another Look at Constant Acceleration • indefinite integral 不定積分 • antiderivative 反導函數

2 -9 Free-Fall Acceleration • freely falling body 自由落體 • free-fall 自由下落 • free-fall acceleration 自由落體加速度、 自由下落加速度 • free space 真空 (vacuum) • g = 9. 8 m/s 2 • a = g = 9. 8 m/s 2

Sample Problem

2 -10 Graphical Integration in Motion Analysis

Sample Problem • • whiplash 鞭索 whiplash injury rear-end collision 追撞 torso 軀幹

Sample Problem