84 CHAPTER 4 • Motion in Two Dimensions x vxi vyi v vxi θ vy v g vxi vy = 0 vxi vy v vi vyi vxi y θ θi θ θi θ ! " # $ % Active Figure 4.7 The parabolic path of a projectile that leaves the origin with a velocity vi. The velocity vector v changes with time in both magnitude and direction. This change is the result of acceleration in the negative y direction. The x component of velocity remains constant in time because there is no accel- eration along the horizontal direction. The y compon

84 CHAPTER 4 • Motion in Two Dimensions x vxi vyi v vxi θ vy v g vxi vy = 0 vxi vy v vi vyi vxi y θ θi θ θi θ ! " # $ % Active Figure 4.7 The parabolic path of a projectile that leaves the origin with a velocity vi. The velocity vector v changes with time in both magnitude and direction. This change is the result of acceleration in the negative y direction. The x component of velocity remains constant in time because there is no accel- eration along the horizontal direction. The y compon