What's the highest velocity airstream a human could generate by lung and lip power alone?

Try dislodging a tick that has got one leg under your skin by breath power. Then try a tweezers; talk about brute strength. However, I can’t answer your question.

Aren’t there medical devices one can puff into to determine lung power (for asthmatics, I believe. But you could certainly do your physics experiment.)

I know that sneezes have been recorded at 300mph+. Also, somone who plays a brass instrument will have very strong lungs, so they’d be the best candidate to find the answer.

Here’s a do-it-yourself gadget that measures Tidal Volume or Vital Capacity of lungs. I’m not sure it will show you velocity or delta V over delta T. But your kids might find it fun.

http://www.biologycorner.com/worksheets/lungcapacity.html

OK, I was able to discover that the lungs can generate up to about 2.8 PSI of pressure, but I’m not sure how to use that to get at my velocity question.

The air speed is affected by the size and shape of the opening that the pressure is released through.

Right, so if I do an explosive “PUH!” sound (which seems to generate the most force), what could you possibly use as the opening size?

Actually, to a certain extent a smaller nozzle opening will create a higher velocity flow. However, if the back pressure (atmospheric pressure) is too high and your lips are pressed together too tightly the flow rate of the air leaving your lungs will be reduced. A combination of the pressure your lungs can exert on the air in them and the variation of the opening of your lips will give you differing velocities. The “PUH!” sound probably gives the most “force” because you are generating both a high pressure in your lungs, and are allowing the unrestricted flow to leave your mouth. If you want the highest velocity, you would do well to close your lips fairly tightly and push hard. It’s rather hard to compute the exact velocity you could attain with your lungs but I would say 150 mph wouldn’t be unheard of.

I also blow bugs off myself. The really tuff ones need added power that can come from a vibrating force. Just blow hard and press your lips together as if you were trying to play a trumpet. The low hormonic vibrations can knock off strong bugs that will not become projectiles with a simple breath or pop. Ticks require the brute force of a tweezers or teeth if you can find a willing companion. (NO…I am not a monkey).

I think the pressure is about 2.8 psi but that is just from unverified internet info.