aerodynamicsaircraft
What happens when a supersonic airplane flies through a cloud? Will it punch a hole or is it more like a bullet through water (= hole closes immediately after the aircraft has passed)?
Is there some special effect because of the supersonic speed? Or maybe the question should be: Does the airflow around an airplane change when the sound barrier is broken?
The physics of a gliding airplane are simple. There is potential energy, proportional to height above the ground. There is also kinetic energy, proportional to speed squared.
First, understand the speed. If the plane isn't slightly nose-heavy, it will fly a scalloped up-down cycle. If it does that, add a little weight to the nose, or distribute the wing area more toward the rear. Assuming you've done that, you control the speed by turning up the trailing edges. The more they are turned up, increasing the angle of attack, the slower it flies. (Up to a maximum angle of attack, at which the wings stop working, or "stall".)
Back to energy. If there were no drag, the plane would never come down. Since there is drag, the drag tends to slow the plane down, decreasing its kinetic energy. Countering that is the plane's tendency to maintain constant speed and kinetic energy, so it descends, turning potential energy into kinetic energy, just like a ball rolling down a slope. So the more drag, the more quickly it descends, the less drag, the more slowly it descends.
A way to minimize drag is to minimize speed, because drag force is proportional to speed squared. (Therefore the sink rate is roughly proportional to speed squared.)
So the speed you trim it for depends on what you want to maximize:
To maximize gliding range, you trim for a speed which is slow enough to have low drag, but not so slow that you don't cover much ground.
To maximize time aloft, you trim for an even slower speed which has even lower drag, thus minimizing the sink rate. This speed is roughly half way between the speed for maximum range and the even slower stall speed $V_S$.
Check these links: V-speeds, and Gliding flight.
Rody and Mike almost got it right. :)
Most aircraft are designed with swept wings. That is the primary mechanism that gives the roll effect to an airplane that may only receive a yaw input. if you look at this picture:
You can see that both wings have a backwards sweep to them. Now, if you introduce a yaw to the aircraft, one wing will extend out more directly into the wind-stream, while the other wing will be even more swept. This effectively makes one wing longer, and the other wing shorter. Like in this image (this image is actually displaying a more extreme case that also involves boundary layer separations, but that is beyond this answer):
Actually, this picture displays it exactly as I was taught in USAF flight school::
The longer wing will generate more lift, and the shorter one will generate less lift. And since there is unequal lift around the roll axis, the airplane will roll, and continue to roll.
Of course, with more lift comes more drag, so that will counter the lift and pull the wing back (Causing an effect known as "Dutch Roll"). Many aircraft have a device called a "yaw damper" to counter this (or else you will feel quite queasy flying). Dutch roll is demonstrated by this GIF:
The reason that Mike's answer is not totally correct is from Figure 2 in his wiki link. Note that the words "non-zero" are included in this diagram:
That means that theoretically, if one were able to yaw an aircraft with dihedral perfectly, the aerodynamic forces would not be the causal factor. Also, most aircraft that have a dihedral or anahedral configuration also have a wing sweep, so that is the overall factor that is at play.
Best Answer
It creates shock waves, which under the right conditions like a supersonic rocket did in this picture, causes concentric cloud rings. Clouds are essentially just volumes where the humidity, temperature, and pressure are such that the air is locally supersatured with water. The craft passing through the cloud will send out waves that disturb the pressure, changing the saturation and causing visible ripples.
EDIT: For a diagram of what is happening here, see this image.