When an object is traveling at terminal velocity
A. it is accelerating.
B. its velocity is zero.
C. the net force on the object is zero.
D. there is an unbalanced force acting on the object.

Question

Ultrilliam · Answer

Terminal velocity means it's traveling the fastest it can go, and can go no faster in free-fall, that said, which one do you think is true?

Mal87 · Answer

I think the answer might be A.

Mal87 · Answer

Or maybe C. I was leaning more towards C

Shadow · Answer

Remember the diagram I drew for you earlier with Bob?

Ultrilliam · Answer

Not quite, accelerating would be the act of going faster, so you can eliminate A.

Mal87 · Answer

Yes I do @Shadow

Shadow · Answer

Drag is the upward force that counters the downward force of gravity.

Shadow · Answer

If you sum the forces in the y direction, it would look like:

$$F_{y} = Drag + Gravity = 0$$

Shadow · Answer

There are zero forces in the horizontal direction. So the Net Force = Forces in the y direction

Mal87 · Answer

Okay I am still kind of confused on this stuff.

Shadow · Answer

Remember, terminal velocity is when an object can't fall any faster because the drag due to air resistance is equal to the force of gravity.

NOpanda14 · Answer

yeah I would have to agree with A

Shadow · Answer

We have already established that's not the correct answer.

Mal87 · Answer

Yes i remember that part.

Shadow · Answer

We can do a process of elimination though. If the velocity were zero, then the object wouldn't be moving. This is incorrect because the object would be falling. If it is falling, it has a velocity.

Mal87 · Answer

Is the velocity zero? So that would probably give you the answer of A

Mal87 · Answer

B i meant

Shadow · Answer

If it's velocity is zero, it's standing still.

NOpanda14 · Answer

b makes more since to me now that I re read it

Shadow · Answer

A falling object is not standing still

Shadow · Answer

@NOpanda14 Stop guessing

Ultrilliam · Answer

^

NOpanda14 · Answer

thats what u think u did say no direct answer

NOpanda14 · Answer

so did u figure it out

Shadow · Answer

A. it is accelerating.
If forces are equal to each other in the upward and downward direction, then it is moving at a constant velocity or it's not moving at all. This is known as a state of equilibrium. The object is not accelerating in this example.

B. its velocity is zero.
The object is falling, therefore it has a displacement over time. Therefore it has velocity.
C. the net force on the object is zero
The net forces are zero because drag = gravity
D. there is an unbalanced force acting on the object.
Incorrect, as drag = gravity and there are no horizontal forces

Shadow · Answer

$$F_{net-force} = F_{y} = +Drag + -Gravity = 0$$

Remember, Drag and Gravity have the same magnitude in terminal velocity, but they are in the opposite directions (Drag, up, Gravity, down), therefore they negate each other.