The answer is Column, however if you want to know the scientific word for it, it is also known as a group
(extra fact, a row is called a period)
Answer:

Explanation:
The velocity v₁ can be calculated with the kinematic formula:

Since the object is initially at rest, v₁ becomes:

Where g is the acceleration due to gravity. Now, the velocity v₂ can be calculated with the same formula, but now the initial velocity is v₁:

Substituting v₁ in this expression and solving for v₂, we get:

Now, dividing v₂ over v₁, we get the expression:

It means that v₂ is √2 times v₁.
The direction of the motion is constantly changing during
motion over any closed path, not only circular.