Answer:
When the drag force on an object falling through the air equals the force of gravity, the object has reached D) terminal velocity.
Explanation:
When an object falls through the atmosphere, it accelerates downwards due to gravity. As the object increases in speed, its air resistance, or drag, increases as well.
If the object falls indefinetely, the drag will increase until drag and gravity are equal. At this point, the object reaches terminal velocity. Newton's second law of motion states that an object's acceleration is directly proportional to the net force acting upon it. Because drag and gravity are equal at terminal velocity, the net force is zero. Therefore, an object at terminal velocity stops accelerating and has reached its maximum velocity.
