Question

An airplane flies at an altitude of 36,000 km and is traveling at a velocity of 300.0 km/h to the north, but the tailwind is 20.0 km/h. What is the airplane's final velocity? (Remember that velocity is a vector.)

Answer 1

I think that I just add the tail wind to the velocity, right?

Answer 2

Right...tailwind = additive, headwind = subtractive :)

Answer 3

Okay, I just wanted to check so that I knew what to do. Thanks y'all :)

Answer 4

Of course, if the tailwind wasn't directly behind the plane you'd have to do vector addition.

Answer 5

Huh? You lost me.. Haha

Answer 6

@demitris So are you saying that I might have to subtract it? Or do nothing to the original? I'm confused...

Answer 7

It could have been worded better for sure but I think the intent is that it's flying at 300 km/h + tailwind.

Answer 8

If you read it the other way then the answer would simply be 300 km/h...since the reading it that way implies that the tailwind is already included in the plane's given velocity.

Answer 9

@theequestrian: What I meant by "Of course, if the tailwind wasn't directly behind the plane you'd have to do vector addition." is this:

Right now the question just states "a tailwind at 20 km/h" without giving any more information...so you can assume the wind is pushing the plane from directly behind the tail. If the question had said something like "a tailwind of 20km/h at 30 degrees east of north"...then you'd have to calculate it using vectors.

Answer 10

@Shane_B Ohh. I see, That makes sense. Thank you!!

Answer 11

you're welcome :)

Answer 12

I really don't like the wording of this question...the answers, depending on how you interpret it, could be 280 km/h, 300 km/h or 320 km/h :(

Answer 13

Yeah, I know.. But I wrote down 320 because it seemed the most logical I suppose. Haha

Answer 14

Tell your teacher that some guy online said he should rewrite the question so that it's more clear :)

Answer 15

Hahaha, I'll make sure to mention it !

Answer 16

What's not clear is whether the 300 km/h given in the problem is before or after including the tailwind. I've also seen a lot of questions like this where the final question is what is the speed of the plane without the tailwind...so it make me wonder if that's what it should be asking.

Oh well :)

@demitris: Yes.. Air France had that issue...

Answer 17

Well...I think their pitot tubes froze so the pilots didn't know what their airspeed was and consequently didn't realize they were in a stall condition.