What causes sound barrier?

Answer 1

The sound barrier to my knowledge, would be the buildup of energy as a plane or vehicle approaches the Speed of sound. It is also visible when something breaks the sound barrier. Check it out on YouTube. It looks like a cloud. So in a way, anyway, it is a barrier, because it is harder to push through than if you were going 200mph.

Answer 2

The sound barrier is something of a myth that dates to the early days of transonic flight. As early airplanes approached the speed of sound, they suffered various flight instabilities--a significant rise in air drag and a tendency for supersonic shock waves to interfere with the operations of control surfaces. Exceeding the speed of sound appeared problematic at the time and the expression "the sound barrier" came into common use. However, there is no real sound barrier. Once Yeager had exceed the speed of sound in an experimental plane, it became clear that the speed of sound was not a firm barrier. However, there is one peculiar thing that does happen once a plane has exceeded the speed of sound. You can no longer hear the plane coming because it is outrunning its own sound waves. Instead of having its sound spread out in front of it, the plane has its sound swept back in a cone behind it. The edges of this cone are a shock wave and you experience a sudden pressure rise as this cone passes across you--you hear a sonic boom. A supersonic plane carries this conical shock wave with it at all times and everyone hears a sonic boom as this shock wave sweeps across them. What you should remember is that the sonic boom doesn't occur when the plane "breaks the sound barrier"; the sonic boom is a continuous feature of a

Answer 3

The Sound Barrier is a pressure wave. When an object accelerates it must push increasing ammounts of air out of the way. This causes pressure to build up. Normally this pressure is relieved through sound when the air molecules transfer their momentum to other molecules creating preaure waves. These pressure waves are what create sound. However these waves can only move so fast. The speed limit is known as the speed of sound or the "sound barrier." When an object's velocity is just bellow the sound barrier the object is moving at the same speed that the air is trying to move out of its way. This causes a build up of air into a pressure wave. This pressure creates a "Wall of Air" in front of the object and this wall takes a great deal of energy to push through. In short the Sound Barrier is formed because air molecules become squeezed together by sound waves until there is little room left for compression.