Posted by shan on Friday, March 7, 2008 at 7:35am.
A jet starts of at a point A and is flying horizontally. And person is standing at a point B on the ground which is to the right of point A. When the jet is directly over the person, the person hears sound coming from point A. The average air temp is 20 deg C. If the speed of the plane at A is 164m/s, what is its speed at B, assuming constant acceleration? The angle between point A and the line of sight of the person on the ground is 36 deg.

physics  drwls, Friday, March 7, 2008 at 7:57am
Let X be the horizontal distance from A to the point above B. Let Vs be the sound speed and Vb be the plane's velocity at point B.
The time required for the plane to fly the distance X is 2X/(164 + Vb), assuming constant acceleration, since (Vb+164)/2 is the average velocity. That equals the time required for the sound to go from A to B, which is X/(Vs*cos36)
Therefore
2/(164+Vb) = 1/Vs*cos36
0.809 Vs = 82 + Vb/2
Vb = 1.608 Vs 168
The sound speed is Vs = 343 m/s, so
Vb = 383 m/s
That is a lot of accleration, going from mach 0.5 to about 1.1

physics  Harry, Wednesday, November 17, 2010 at 12:39pm
Angle's actually 56 degrees...
Answer This Question
Related Questions
 math  A military jet flies directly over and at a right angles to the straight...
 calculus  A military jet flies directly over and at a right angles to the ...
 math  A jet flew at an average speed of 480 mph from Point X to Point Y. ...
 physics  1. A jet is flying with an air speed of 500 m/s. A parcel is dropped ...
 physics  1. A jet is flying with an air speed of 500 m/s. A parcel is dropped ...
 Math  In this diagram, one person is standing at point A, one person is at ...
 physics  Two people take identical jet skis across a river, traveling at the ...
 physics  A fighterjet is in level flight at an altitude of 400m and with a ...
 college physics  A fighterjet is in level flight at an altitude of 400m and ...
 Physics  A jet pilot is in a vertical loop. If the jet is moving at a speed of ...
More Related Questions