# My daughter's homework question (math/trigonometry) **URL:** \ **Category:** Factual Questions\ **Created:** [February 1, 2022, 6:23pm UTC](https://boards.straightdope.com/t/my-daughters-homework-question-math-trigonometry/958756 "2022-02-01T18:23:39Z")\ **Posts on this page:** 20\ **Page:** 2
**Author:** ![Nars\_Glinley](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/nars_glinley/32/8177_2.png) [@Nars\_Glinley](https://boards.straightdope.com/u/Nars_Glinley)\ **Post date:** [February 1, 2022, 9:39pm UTC](https://boards.straightdope.com/t/my-daughters-homework-question-math-trigonometry/958756/21 "2022-02-01T21:39:55Z")
Is the plane on a treadmill? ---
**Author:** ![EdelweissPirate](https://avatars.discourse-cdn.com/v4/letter/e/8491ac/32.png) [@EdelweissPirate](https://boards.straightdope.com/u/EdelweissPirate)\ **Post date:** [February 1, 2022, 11:15pm UTC](https://boards.straightdope.com/t/my-daughters-homework-question-math-trigonometry/958756/22 "2022-02-01T23:15:02Z")
“Frictionless chicken” is funny because of the repeated vowel sound. “Spherical cows” is an old, old joke about the utility of approximations, as we all know. But I get annoyed when folks invoke “spherical cows” in response to any approximation at all. If you don’t make approximations and SWAGs, you won’t get anywhere at all—foolish consistency is the hobgoblin of small minds, as it were. I’m definitely not accusing the OP of this, to be clear. ---
**Author:** ![burpo\_the\_wonder\_mutt](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/burpo_the_wonder_mutt/32/365_2.png) [@burpo\_the\_wonder\_mutt](https://boards.straightdope.com/u/burpo_the_wonder_mutt)\ **Post date:** [February 1, 2022, 11:24pm UTC](https://boards.straightdope.com/t/my-daughters-homework-question-math-trigonometry/958756/23 "2022-02-01T23:24:32Z")
So, if I bring up how no one has mentioned how the Earth’s circumference plays into this little homework assignment then I’m a hobgoblin? [**COOL!!**](https://youtu.be/jJw8gw0F6gI?t=22) ---
**Author:** ![3AxisCtrl](https://avatars.discourse-cdn.com/v4/letter/3/ecd19e/32.png) [@3AxisCtrl](https://boards.straightdope.com/u/3AxisCtrl)\ **Post date:** [February 1, 2022, 11:48pm UTC](https://boards.straightdope.com/t/my-daughters-homework-question-math-trigonometry/958756/24 "2022-02-01T23:48:27Z")
> [@yearofglad](#): > > … and the mountain is 12,640 feet tall. You need to add the plane’s initial altitude (2000’). ---
**Author:** ![3AxisCtrl](https://avatars.discourse-cdn.com/v4/letter/3/ecd19e/32.png) [@3AxisCtrl](https://boards.straightdope.com/u/3AxisCtrl)\ **Post date:** [February 1, 2022, 11:53pm UTC](https://boards.straightdope.com/t/my-daughters-homework-question-math-trigonometry/958756/25 "2022-02-01T23:53:53Z")
It’s no mean feat for a plane to maintain a rate of climb better than 3000 fpm. ---
**Author:** ![Folly](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/folly/32/3219_2.png) [@Folly](https://boards.straightdope.com/u/Folly)\ **Post date:** [February 1, 2022, 11:56pm UTC](https://boards.straightdope.com/t/my-daughters-homework-question-math-trigonometry/958756/26 "2022-02-01T23:56:52Z")
> [@3AxisCtrl](#): > > It’s no mean feat for a plane to maintain a rate of climb better than 3000 fpm… When the alternative is hitting a mountain… ---
**Author:** ![48Willys](https://avatars.discourse-cdn.com/v4/letter/4/db5fbb/32.png) [@48Willys](https://boards.straightdope.com/u/48Willys)\ **Post date:** [February 2, 2022, 6:20am UTC](https://boards.straightdope.com/t/my-daughters-homework-question-math-trigonometry/958756/27 "2022-02-02T06:20:31Z")
Climbing at 20 degrees is not the _only option_. Another alternative is to circle to gain altitude. So says the pilot of a Cessna 172 in the Rocky Mountains. I do it frequently. I also fly through passes & gaps between peaks. ---
**Author:** ![burpo\_the\_wonder\_mutt](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/burpo_the_wonder_mutt/32/365_2.png) [@burpo\_the\_wonder\_mutt](https://boards.straightdope.com/u/burpo_the_wonder_mutt)\ **Post date:** [February 2, 2022, 1:12pm UTC](https://boards.straightdope.com/t/my-daughters-homework-question-math-trigonometry/958756/28 "2022-02-02T13:12:41Z")
^ Wow! that is some Jeep! 😄 ---
**Author:** ![GaryM](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/garym/32/241_2.png) [@GaryM](https://boards.straightdope.com/u/GaryM)\ **Post date:** [February 2, 2022, 4:49pm UTC](https://boards.straightdope.com/t/my-daughters-homework-question-math-trigonometry/958756/29 "2022-02-02T16:49:35Z")
I’ve not piloted a plane in a long time, but I seem to remember that simply pointing the nose at a steeper angle does necessarily increase altitude. Throttle controls altitude and attitude controls airspeed. Assuming the aircraft is trimmed for level flight of course. ---
**Author:** ![abcdefghij](https://avatars.discourse-cdn.com/v4/letter/a/43a26b/32.png) [@abcdefghij](https://boards.straightdope.com/u/abcdefghij)\ **Post date:** [February 2, 2022, 5:02pm UTC](https://boards.straightdope.com/t/my-daughters-homework-question-math-trigonometry/958756/30 "2022-02-02T17:02:31Z")
It’s a much more challenging trigonometry problem to ask how many chandelles need to be completed to clear the mountain. ---
**Author:** ![amarinth](https://avatars.discourse-cdn.com/v4/letter/a/3be4f8/32.png) [@amarinth](https://boards.straightdope.com/u/amarinth)\ **Post date:** [February 2, 2022, 8:02pm UTC](https://boards.straightdope.com/t/my-daughters-homework-question-math-trigonometry/958756/31 "2022-02-02T20:02:17Z")
Got the same answer using the general idea (more or less), then I started to second guess myself because 2000 → 14000 feet in 5 minutes seemed like quite a lot and I was a bit concerned that I had done something wrong with units, and also don’t planes usually fly at twenty or thirty thousand feet? My “does this answer make sense?” intuition was not happy with this question. Then again, I know nearly nothing about flying. ---
**Author:** ![abcdefghij](https://avatars.discourse-cdn.com/v4/letter/a/43a26b/32.png) [@abcdefghij](https://boards.straightdope.com/u/abcdefghij)\ **Post date:** [February 2, 2022, 8:21pm UTC](https://boards.straightdope.com/t/my-daughters-homework-question-math-trigonometry/958756/32 "2022-02-02T20:21:28Z")
> [@amarinth](#): > > also don’t planes usually fly at twenty or thirty thousand feet? Not planes that fly at 100 mph. Of course, those planes can’t pull off 3000 fpm, either. ---
**Author:** ![Lance\_Turbo](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lance_turbo/32/6156_2.png) [@Lance\_Turbo](https://boards.straightdope.com/u/Lance_Turbo)\ **Post date:** [February 3, 2022, 1:40am UTC](https://boards.straightdope.com/t/my-daughters-homework-question-math-trigonometry/958756/33 "2022-02-03T01:40:14Z")
> [@amarinth](#): > > Then again, I know nearly nothing about flying. Obviously. You never even thought to ask if the plane was on a treadmill. ---
**Author:** ![Richard\_Pearse](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/richard_pearse/32/13144_2.png) [@Richard\_Pearse](https://boards.straightdope.com/u/Richard_Pearse)\ **Post date:** [February 3, 2022, 5:19am UTC](https://boards.straightdope.com/t/my-daughters-homework-question-math-trigonometry/958756/34 "2022-02-03T05:19:20Z")
This is true. The question gets around these technicalities by simply saying the plane was flown at an angle of 20º. ---
**Author:** ![Isilder](https://avatars.discourse-cdn.com/v4/letter/i/cc9497/32.png) [@Isilder](https://boards.straightdope.com/u/Isilder)\ **Post date:** [February 3, 2022, 11:01am UTC](https://boards.straightdope.com/t/my-daughters-homework-question-math-trigonometry/958756/35 "2022-02-03T11:01:01Z")
But an aviator would then instantly take that to be pitch of 20 degrees. And given we don’t know the wind , then we might assume that the airspeed number is really groundspeed, or else we can’t work it out … But oh well, we know its meant to be simple trig and so for that purpose, the angle is the flight track angle, not pitch, and airspeed is meant to be the rate along that track, roof speed if he was a person running up a roof. ---
**Author:** ![Gyrate](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/gyrate/32/3588_2.png) [@Gyrate](https://boards.straightdope.com/u/Gyrate)\ **Post date:** [February 3, 2022, 11:41am UTC](https://boards.straightdope.com/t/my-daughters-homework-question-math-trigonometry/958756/36 "2022-02-03T11:41:20Z")
“Now assume that the plane collides with an unladen swallow…” ---
**Author:** ![GaryM](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/garym/32/241_2.png) [@GaryM](https://boards.straightdope.com/u/GaryM)\ **Post date:** [February 3, 2022, 2:48pm UTC](https://boards.straightdope.com/t/my-daughters-homework-question-math-trigonometry/958756/37 "2022-02-03T14:48:03Z")
European or African? ---
**Author:** ![Gyrate](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/gyrate/32/3588_2.png) [@Gyrate](https://boards.straightdope.com/u/Gyrate)\ **Post date:** [February 3, 2022, 2:48pm UTC](https://boards.straightdope.com/t/my-daughters-homework-question-math-trigonometry/958756/38 "2022-02-03T14:48:42Z")
I don’t knowwwAAAAAAAAaaaaaggh… splut ---
**Author:** ![Richard\_Pearse](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/richard_pearse/32/13144_2.png) [@Richard\_Pearse](https://boards.straightdope.com/u/Richard_Pearse)\ **Post date:** [February 3, 2022, 4:01pm UTC](https://boards.straightdope.com/t/my-daughters-homework-question-math-trigonometry/958756/39 "2022-02-03T16:01:49Z")
> [@Isilder](#): > > But an aviator would then instantly take that to be pitch of 20 degrees. > > And given we don’t know the wind , then we might assume that the airspeed number is really groundspeed, or else we can’t work it out … > > But oh well, we know its meant to be simple trig and so for that purpose, the angle is the flight track angle, not pitch, and airspeed is meant to be the rate along that track, roof speed if he was a person running up a roof. I’m an aviator, I didn’t take it to be a pitch of 20º (didn’t even cross my mind.) Airspeed can only mean airspeed. We aren’t given any wind, so assume wind is zero. My instant take on the question was that it is a trig question not a flying question. I jumped to your last paragraph immediately because I understood the context of the question. ---
**Author:** ![3AxisCtrl](https://avatars.discourse-cdn.com/v4/letter/3/ecd19e/32.png) [@3AxisCtrl](https://boards.straightdope.com/u/3AxisCtrl)\ **Post date:** [February 3, 2022, 4:11pm UTC](https://boards.straightdope.com/t/my-daughters-homework-question-math-trigonometry/958756/40 "2022-02-03T16:11:03Z")
> [@Richard\_Pearse](#): > > Airspeed can only mean airspeed. Were we in a mood to quibble (rare, of course, for the SDMB - but bear with me here) we could dive into such things as the difference between indicated and true airspeed. (Aircraft capable of a steady 100 mph rarely offer their pilot any direct display of the latter.) [Previous page](https://boards.straightdope.com/t/my-daughters-homework-question-math-trigonometry/958756.md?page=1) [Next page](https://boards.straightdope.com/t/my-daughters-homework-question-math-trigonometry/958756.md?page=3)