1-D kinematics Velocity v is the rate of change of position Average velocity Vay in the time A t=t-t is △t X X trajectory △Ⅹ Vay slope of line connecting x, and X2 X △t Physics 121: Lecture 4, Pg 12Physics 121: Lecture 4, Pg 12 1-D kinematics t x t t x x v f i f i av   = − −  Velocity v is the “rate of change of position” Average velocity vav in the time  t = tf - t i is: t x t1 t2  x x 1 x 2 trajectory  t Vav = slope of line connecting x1 and x2