Chapter 4.3, Problem 4.2QQ

(i) As a projectile thrown at an upward angle moves in its parabolic path (such as in Fig. 4.9), at what point along its path are the velocity and acceleration vectors for the projectile perpendicular to each other? (a) nowhere (b) the highest point (c) the launch point (ii) From the same choices, at what point are the velocity and acceleration vectors for the projectile parallel to each other?