Physics

posted by .

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 -

    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).

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. Math

    A plane passes directly over you head at an altitude of 500 feet. Two seconds later you observe that is angle of elevation is 42 degrees. How far did the plane travel in 2 seconds?
  2. Physics

    A supersonic jet travels at 3.0 Mach (i.e. at three times the speed of sound). It cruises at 20,000 m above the ground. we choose t=0 when the plane passes directly overhead of an observer. At what time t will the observer hear the …
  3. advance geometry

    A plane is flying east, ascending at a constant angle. Jack is standing on the ground, watching the plane come to (horizontally) directly at him. When he first sees the plane, at an angle of elevation of 15 degrees, its horizontal …
  4. physics

    A plane can fly at Mach 1.47, which means the speed of the plane is 1.47 times the speed of sound in air. What is the angle between the direction of propagation of the shock wave and the direction of the plane's velocity?
  5. Pre-Calculus-Trig

    A woman on the top of a 448 foot high building spots a small plane. As she views the plane, its angle of elevation is 62 degrees. At the same instant a man at the ground-level entrance to the entrance to the building sees the plane …
  6. Calculus

    At a given moment, a plane passes directly above a radar station at an altitude of 7 miles. (a) If the plane's speed is 400 mph, how fast is the distance between the plane and the station changing half an hour later?
  7. Trigonometry

    A jet plane flying 6000 m above the ground passed directly above Ana. one minute later, Ana noticed that the plane's angle of elevation was 18 degrees 34 minutes. What was the horizontal distance covered by the plane?
  8. physics

    A plane is found by radar to be flying 5.9 km above the ground. The angle of elevation from the radar to the plane is 78.6°. Ten seconds later, the plane is directly over the station. Find the speed of the plane, assuming that it …
  9. Physics

    A small plane aims to fly directly east at 120. km/h, but a headwind is blowing 50. km/h at 22 degrees south of west, slowing the plane down. Find the plane's actual ground speed and direction.
  10. Maths

    You wonder what altitude the plane reached when it was directly above the end of the runway and how far it travelled to get to that point. You know the runway tarmac is 5500 metres long and approximate that when the plane left the …

More Similar Questions