Answer:
Equal to the weight of the object
Explanation:
There are two forces acting on the object hanging on the string:
- The tension in the string, T, acting upward
- The weight of the object, mg, acting downward
We can write Newton's second law as:

where a is the acceleration of the object.
Here we are told that the elevator is moving at constant speed: this means that the acceleration of the object is zero, therefore a = 0 and the equation becomes

therefore, the tension in the string is equal to the weight of the object.
You can tell that it has reached its terminal velocity when D) the leaf is falling with a constant velocity as you are watching the leaf fall. The terminal velocity is a point of condition when an object's speed equalize the force of gravity. The terminal velocity condition could occur if there is no acceleration to the object's speed<span>.</span>