普通物理学Ⅰ（H）exercise-lesson1-14-1.pdf

Exercise Lesson REVIEW Position Vector     r xi yj zk      r t ( ) x t (i )y t (j) z t (k)  Motion Equation Displacement    r r r B A 2014-3-12 phypzq@zju.edu.cn 1 2014-3-12 1 Exercise Lesson Velocity   r Averg Velocity v t Instantaneous velocity    Δr dr v lim Δt 0 Δt dt  d  d  dy  r x 2 2 v j v i v v  dt dt dt x y 2014-3-12 phypzq@zju.edu.cn 2 2014-3-12 2 Exercise Lesson Speed s Averg Speed v t Instantaneous Speed ds  v v d