physics of flying?

Question

just wondering..when mosquitos(or any other flying animal) fly, is it true that they are exerting a force downwards(by flapping their wings),thus by newton's third law there'll be a reaction force(lift) which pushes them up.

if that is true, why mosquitos dont exist on higher altitudes?is it because of the force needed to push them is too much?or is it something to deal with pressure difference??

please answer using physics concepts,thank you.

Answer 1

******** natalie ... just wanted to clear up a common misconception about Bernoulli and flight ...

The air travels faster over the top of the curved wing , than the bottom, but not due to the greater distance over the top.

" The falsehood is not due to Bernoulli's law, which is well proven, but rather due to falseness of the principle of equal transit times." .... from the Link provided below..

The Bernoulli Effect may help explain some of the lift of the mosquito, since the wings are being flapped, vs the airplanes forward movement thru air, [ and the mosquito is very light, so Bernoulli may have some effect, but I doubt it...]. The lift is more likely the result of Newton's Laws, and reaction force... the wings push down, the air pushes back up...

For those interested in why the Bernoulli effect is not the reason for lift, and to dispel the "hump theory" of wings, see the links below ....

"Stop Abusing Bernoulli... Why airplanes really fly " and "How Airplanes Fly"

Answer 2

Actually, flying insects such as mosquitos do not fly due solely to Newtons third law, but also due to another principle known as the Bernoulli effect. The downward force exerted by the wings does push some air downward, yes, which is Newtonian, and then they angle their wings to allow air to slip past on the up-stroke, esentially climbing their way up the air.
but flying creatures are also held aloft due to the fact that faster moving air literally sucks. when the wing pushes downward, it fills with air and bows upward. The air rushing past the bottom of the wing only has to travel a short distance from the leading edge to the back edge, so it moves slower. That, plus the higher air pressure made by the downstroke pushes the bug upwards. The air flowing over the TOP of the wing though, has to flow a longer distance over that bowed curve, not straight across from one edge to the other. That means, to catch up to the air below the wing, it has to travel faster, which causes a drop in air pressure, which sucks the bug upwards. All these factors combine to loft the bug into the air and keep it there, even though the bugs wings are not as aerodynamic as they could be.
The reason you don't find mosquitos on mountain tops is that they need pools of warm stagnant water to breed in, and there aren't many up there. Mosquitos like it warm and wet, and high altitudes are cold and dry. Also, it gets windy more often up there, which tends to blow the bugs away.
Furthermore, bugs go where the food is, and you don't find a lot of exposed skin to bite on snowy mountains. What animals you do find are covered in thick coats of shaggy fur, or artificial fur known as parkas and high altitude gear, which all tend to be too thick to bite through.

Answer 3

I don't know about high altitude mosquitoes but they do sustain flight by pushing down against the air. So do airplanes, helicopters and birds. The effect of wing camber which Natalie described in the above answer makes airfoils more efficient than non-cambered foils but unless it pushes air down no insect or bird or airplane will stay up.

Answer 4

I suspect that the answer isn't a matter of flight physics. Mosquitos must have water in which to breed, and a lot of traffic in warm-blooded animals like us on which to feed. You don't get a lot of either at very high altitudes. I think there are birds that like to live at high altitudes--the Andean condor does--and they seem to fly well enough.

Answer 5

Its because air becomes lesser and lesser denser as you go up the atmosphere.

Mosquitos etc.. can push down a maximum volume of air using their wings.. When you go higher and higher the same volume of air has lesser and lesser weight.. So when the weight of the air thats pushed down becomes less than the weight of the mosquito..it cant fly and it will fall...