A rock is thrown straight up, reaches a maximum height, which of the following describes the motion at the maximum height?
At the maximum height, the motion of the rock can be described as momentarily coming to a stop, reaching its peak height, and reversing direction.
To describe the motion of a rock at its maximum height after being thrown straight up, we need to consider the forces acting on the rock and the principles of projectile motion.
When the rock is thrown straight up, it experiences the force of gravity acting in the downward direction. As it moves upward, the force of gravity causes it to gradually slow down until it reaches its highest point, also known as the maximum height.
At the maximum height, the motion of the rock briefly comes to a stop before it starts falling back down due to the force of gravity. This means that the velocity of the rock is momentarily zero at the maximum height.
Additionally, the acceleration of the rock at the maximum height will be equal to the acceleration due to gravity, which is approximately 9.8 m/s² near the Earth's surface. However, at the exact moment the rock reaches its highest point, the acceleration vector changes direction from upward to downward.
Therefore, the correct description of the motion of the rock at the maximum height is that it momentarily comes to a stop, with a velocity of zero, before it begins to fall back down due to the force of gravity.
There are no "following" to choose among.
Don't you realize that?