Mathematical and Physical Journal
for High Schools
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Problem P. 4300. (December 2010)

P. 4300. After leaving the runway a supersonic fighter begins to ascend along a straight line of angle of elevation of 30o. Due to the the abrupt sound wave the grass in the fields around the runway spread out in a parabolic shape. What is the speed of the fighter?

(5 pont)

Deadline expired on January 10, 2011.


Sorry, the solution is available only in Hungarian. Google translation

Megoldás. A gép által kibocsátott hang kúp alakú hullámfrontjának és a vízszintes mezőnek a metszete akkor lesz éppen parabola, ha a hangkúp félnyílásszöge egyenlő az emelkedési szöggel. Ebből a feltételből a vadászgép sebességére a hangsebesség kétszerese adódik, azaz 2 Mach.


Statistics:

62 students sent a solution.
5 points:51 students.
4 points:1 student.
3 points:4 students.
2 points:2 students.
1 point:2 students.
0 point:1 student.
Unfair, not evaluated:1 solution.

Problems in Physics of KöMaL, December 2010