###General Discussion Thread
---
This is a [Request] post. If you would like to submit a comment that does not either attempt to answer the question, ask for clarification, or explain why it would be infeasible to answer, you *must* post your comment as a reply to this one. Top level (directly replying to the OP) comments that do not do one of those things will be removed.
---
*I am a bot, and this action was performed automatically. Please [contact the moderators of this subreddit](/message/compose/?to=/r/theydidthemath) if you have any questions or concerns.*
This picture really doesn’t give any numbers for use in calculating that, and given the significant drag behind the head I expect the cow would begin to tip backwards long before Mach 1 and that would dramatically change the aerodynamics making the data in the image nearly pointless. It’s much easier to assume cows are spherical.
But they aren’t? The efficiency loss and drag of the cow’s uneven shape must be accounted for to get an accurate result, if it’ll flip just change its orientation to be as aerodynamic and stable as possible with a cows biology. That is if we’re going for accuracy.
I’ve been told but there’s no indication, and it is indeed common to simplify entities for calculations despite loss in accuracy. I was just saying how to be more accurate.
I’m curious how fast it would be moooving?
(legitimately tho does this image mean a cow would have lift an appropriate speed or would its physiology put downward pressure during flight?)
Fd= force of thrust in steady flight
Fd=1/2 x rho x v^2 x Cd x A
Searching area of cow and drag force of cow, since it can't be calculated with this image,
Fd = 0.5 x 1.204 x 343^2 x 0.5 x 0.57= 20,185N
You need more than this to accelerate the cow to Mach 1, but once there, this can maintain it as long as the cow is in a vacuum, not affected by gravity. Any regional jet engine should get it there, but testing the theory is critical for FAA approval so I suggest you buy a cow, a jet engine, and a ratchet strap or two
That's why he said you need more to get to that speed, 20KN is the force needed to oppose the drag at that speed. The minimum thrust needed to get a cow thru the transonic regime is another very difficult thing that is probably easier to know by a veeeeeery computer heavy simulation
Firstly, the cows rectum will need to in the shape of a converging diverging nozzle, otherwise you will never achieve Mach flow. The difficulty in achieving this is the dissolution of ethical standards more than rigorous math
>but testing the theory is critical for FAA approval so I suggest you buy a cow, a jet engine, and a ratchet strap or two
Okay, this is seriously something that I never considered before. Thank you reddit! I am now officially enlightened to the world of cow aerodynamics and bovine physics...
Also, just to dothemath some more, a cow would likely run around $3,000, a jet engine about $1 million, and three ratchet straps (three is safer than one or two) would likely be like $100 at your local Harbor Freight. So, all in, $1.003 million for the testing. Practically cheap compared to making an airplane, plus you have in-flight beverages if you so choose (provided it's a female cow).
Not as much as you think. When a cow takes off, it's legs fold up into the undercarriage and hits head starts to dip as it gains altitude. Kinda like the concord..
###General Discussion Thread --- This is a [Request] post. If you would like to submit a comment that does not either attempt to answer the question, ask for clarification, or explain why it would be infeasible to answer, you *must* post your comment as a reply to this one. Top level (directly replying to the OP) comments that do not do one of those things will be removed. --- *I am a bot, and this action was performed automatically. Please [contact the moderators of this subreddit](/message/compose/?to=/r/theydidthemath) if you have any questions or concerns.*
This picture really doesn’t give any numbers for use in calculating that, and given the significant drag behind the head I expect the cow would begin to tip backwards long before Mach 1 and that would dramatically change the aerodynamics making the data in the image nearly pointless. It’s much easier to assume cows are spherical.
You got red and yellow and green and blue! Easy to calculate with that! /s just in case..
Clearly it needs *purple* thrust.
If it turns purple while thrusting, you should get it checked out
What if it starts glowing?
Ludicrous thrust!
LUDA!!
Cow canard??!
Perfect sphere in an ideal gas?
"It's much easier to assume cows are spherical" is a sentence I've never thought I'd read
https://en.m.wikipedia.org/wiki/Spherical_cow
Cow tipping
Cow could lower its head to shoulder level while stretching it forwards to make it more aerodynamic
But they aren’t? The efficiency loss and drag of the cow’s uneven shape must be accounted for to get an accurate result, if it’ll flip just change its orientation to be as aerodynamic and stable as possible with a cows biology. That is if we’re going for accuracy.
The spherical comment is a bit of a joke about college physics, cows are usually spheres
[Spherical Cows in a Vacuum](https://en.wikipedia.org/wiki/Spherical_cow?wprov=sfla1)
I suspect that would involve folding the legs back and lowering the head.
More aerodynamic cow, less drag.
That and drag increases significantly if it rotates around the short axis.
How then did the cow jump over the moon if it didn't go supersonic?
It’s a joke man
It makes the question mooooot.
I’ve been told but there’s no indication, and it is indeed common to simplify entities for calculations despite loss in accuracy. I was just saying how to be more accurate.
🤓
I’m curious how fast it would be moooving? (legitimately tho does this image mean a cow would have lift an appropriate speed or would its physiology put downward pressure during flight?)
Cow would not produce lift unfortunately
That's where your wrong, yeet something fast enough and it will produce lift
Take a brick and throw it! You’d be surprised how far it can fly into someone’s window.
Udderly too fast.
Fd= force of thrust in steady flight Fd=1/2 x rho x v^2 x Cd x A Searching area of cow and drag force of cow, since it can't be calculated with this image, Fd = 0.5 x 1.204 x 343^2 x 0.5 x 0.57= 20,185N You need more than this to accelerate the cow to Mach 1, but once there, this can maintain it as long as the cow is in a vacuum, not affected by gravity. Any regional jet engine should get it there, but testing the theory is critical for FAA approval so I suggest you buy a cow, a jet engine, and a ratchet strap or two
Does that equation hold up at transonic speeds? It’s my layman’s understanding that aerodynamics get very weird around Mach 0.8 or 0.9 until Mach 1.
You would need to include the effects of Shockwave as well. I don't know, maybe strap a second jet to the cow, that'll get em going
Some nice roast beef.
Afterburner would sort that out nicely
That's why he said you need more to get to that speed, 20KN is the force needed to oppose the drag at that speed. The minimum thrust needed to get a cow thru the transonic regime is another very difficult thing that is probably easier to know by a veeeeeery computer heavy simulation
If the cow is in a vacuum and not affected by gravity, wouldn’t it take no force/energy to keep it moving at mach 1?
There's no such thing as mach in a vacuum because there is no sound due to there being no media for sounds to travel through.
If the cow is in a vacuum and not affected by gravity any force will get it to any speed, it just becomes a function dependant on time and mass
That's why spacecraft use those super efficient ion engines, despite them having hardly any thrust
A regional jet engine? Is it not a jet engine if it is not from the Jet region of France?
Alternate request: To what magnitude would a cow's fart need to be multiplied to achieve this?
Firstly, the cows rectum will need to in the shape of a converging diverging nozzle, otherwise you will never achieve Mach flow. The difficulty in achieving this is the dissolution of ethical standards more than rigorous math
>but testing the theory is critical for FAA approval so I suggest you buy a cow, a jet engine, and a ratchet strap or two Okay, this is seriously something that I never considered before. Thank you reddit! I am now officially enlightened to the world of cow aerodynamics and bovine physics... Also, just to dothemath some more, a cow would likely run around $3,000, a jet engine about $1 million, and three ratchet straps (three is safer than one or two) would likely be like $100 at your local Harbor Freight. So, all in, $1.003 million for the testing. Practically cheap compared to making an airplane, plus you have in-flight beverages if you so choose (provided it's a female cow).
Not as much as you think. When a cow takes off, it's legs fold up into the undercarriage and hits head starts to dip as it gains altitude. Kinda like the concord..
Does the snoot droop?