Chapter 0 Preface Motion with changing speed How to find the instantaneous speed at t1? (4)=历s(2)-s(1)1=t 2=t+△t Derivative of s v(t)=lin S(t+△)-s(t)ds △t→>0 △t dtChapter 1Chapter 1 Measurment Chapter 0 Preface How to find the instantaneous speed at t1? 2 1 2 1 1 ( ) ( ) ( ) lim 2 1 t t s t s t v t t t − − = → • Motion with changing speed t s t t s t v t t  +  − =  → ( ) ( ) ( ) lim 0 t = t 1 t = t + t 2 dt ds = Derivative of s