Правка разделов «Statement», «Solution», «Answer»
en/3.7.13.md
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| ### Statement | |||
| − | $3.7.13.$ [Insert the problem statement] | ||
| + | $3.7.13.$ The region of increased pressure at the boundary of the medium propagates to the right with a speed $v$ greater than the speed of sound $c$ in the medium. What is the wave front in the medium? What is the direction of its propagation? | ||
| ### Solution | |||
| − |  | ||
| Let $A$ and $B$ be previous and current positions of the source and $C$ be a point on the wavefront. Then, $AC/AB=c/v$, so the envelope of emitted spherical waves is the surface of a cone. The angle between the wavefront and the direction of the source is $\alpha=\arcsin(c/v)$. | |||
| #### Answer | |||
| − | |||
| + | A conical wavefront making an angle $\alpha=\arcsin(c/v)$ with the direction of the source. | ||
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| ### Statement | ### Statement | ||
| $3.7.13.$ [Insert the problem statement] | $3.7.13.$ The region of increased pressure at the boundary of the medium propagates to the right with a speed $v$ greater than the speed of sound $c$ in the medium. What is the wave front in the medium? What is the direction of its propagation? | ||
| ### Solution | ### Solution | ||
|  | ||
| Let $A$ and $B$ be previous and current positions of the source and $C$ be a point on the wavefront. Then, $AC/AB=c/v$, so the envelope of emitted spherical waves is the surface of a cone. The angle between the wavefront and the direction of the source is $\alpha=\arcsin(c/v)$. | Let $A$ and $B$ be previous and current positions of the source and $C$ be a point on the wavefront. Then, $AC/AB=c/v$, so the envelope of emitted spherical waves is the surface of a cone. The angle between the wavefront and the direction of the source is $\alpha=\arcsin(c/v)$. | ||
| #### Answer | #### Answer | ||
| A conical wavefront making an angle $\alpha=\arcsin(c/v)$ with the direction of the source. | |||