Posted by **Becca** on Sunday, October 4, 2009 at 1:35pm.

Watching a jet plane fly high over my head, I noticed that the sound seemed to be coming from directly above me when the plane was at an angle of 30 degrees from vertical. How fast was the plane flying? Assume the speed of sound was 330 m/s.

- Physics -
**MathMate**, Sunday, October 4, 2009 at 2:51pm
Let the plane be H m above the observer.

Time taken for sound to reach observer, t

= H/330 s

Distance plane travelled in time t, D

=H sin(30°) m

Speed of plane

= distance / t

= D/t

= H sin(30°) / (H/330) m/s

= 330 sin(30°) m/s

Convert to km/h if necessary (multiply by 3.6).

## Answer this Question

## Related Questions

- Trigonometry - A jet plane flying 6000 m above the ground passed directly above ...
- advance geometry - A plane is flying east, ascending at a constant angle. Jack ...
- Physics - A supersonic jet travels at 3.0 Mach (i.e. at three times the speed of...
- physics - A plane can fly at Mach 1.47, which means the speed of the plane is 1....
- physics - A plane is found by radar to be flying 5.9 km above the ground. The ...
- physics - A jet starts of at a point A and is flying horizontally. And person is...
- Math - A plane passes directly over you head at an altitude of 500 feet. Two ...
- physics - A 6 N box is projected with a velocity of 2 m/s at the bottom of the ...
- math - an airplane is flying at a height of 2 miles above the level ground. the ...
- 8th Grade Algebra - I don't know how to do these types of problems whatsoever. 1...