A missile is fired over horizontal ground at an angle of 8.50°. At what point on the trajectory are [(v)\vec] and [(a)\vec] parallel to each other?
At the end of the trajectory.
At the beginning of the trajectory.
At the top of the trajectory.
There is no point where v and a are parallel to each other.
since all the acceleration is due to gravity, which is just downward,
pick D
To determine at what point on the trajectory [(v)\vec] and [(a)\vec] are parallel to each other, we need to consider the motion of the missile.
When a projectile is fired at an angle to the ground, it follows a curved path called a trajectory. At any given point on the trajectory, the velocity [(v)\vec] and acceleration [(a)\vec] are vectors.
At the beginning of the trajectory, when the missile is just fired, the velocity vector [(v)\vec] is tangent to the trajectory, while the acceleration [(a)\vec] is directed downward due to gravity. Since the velocity and acceleration vectors have different directions, they are not parallel at the beginning of the trajectory.
At the top of the trajectory, the missile reaches its highest point and momentarily comes to rest before falling back to the ground. At this point, the velocity vector [(v)\vec] is horizontal (parallel to the ground) and the acceleration [(a)\vec] is directed vertically downward. Therefore, at the top of the trajectory, the velocity and acceleration vectors are not parallel.
At the end of the trajectory, when the missile hits the ground, the velocity vector [(v)\vec] and acceleration [(a)\vec] are not parallel. The acceleration is directed vertically downward due to gravity, while the velocity vector is determined by the angle at which the projectile was fired.
Therefore, the correct answer is: There is no point where [(v)\vec] and [(a)\vec] are parallel to each other.