What Is the Landing Distance of the Enmeshed Spy Plane and Rocket?

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The discussion revolves around calculating the landing distance of an enmeshed spy plane and rocket after a collision. The spy plane, weighing 575 kg, is traveling north at 450 m/s, while the rocket, weighing 1280 kg, is moving east at 725 m/s. Using conservation of momentum and the Pythagorean theorem, the resulting velocity after the collision is calculated to be approximately 519.35 m/s. The time to fall from an altitude of 2700 m is determined to be around 23.46 seconds. The initial calculations for distance yield results that do not match the expected answer, prompting participants to seek clarification and potential errors in their approach.
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In a military test, a 575 kg unmanned spy plane is traveling north at an altitude of 2700 m and a speed of 450 m/s. It is intercepted by a 1280 kg rocket traveling east at 725 m/s. If the rocket and spy plane become enmeshed in a tangled mess, how far from the point of impact do they hit the ground?

O.K. I take the plane is traveling northward parrallel to the ground. Conservation of momentum- and pythagorean theorum yields-
sqrt((1280 x 725)^2+(450 x 575)^2) = (1280 +575)V
Solving for V gives 519.35, and it is now a projectile motion. Solving for the time would give
-2700 = -4.905t^2
which gives time 23.46
then, I multiplied velocity x time, which gave 1.22 x 10^4, which was not the right answer. Then I saw it said distance from explosion, so it would be the hypotenuse of a 1.22 x 10^4 by 2700 triangle, giving 1.25 x 10^4.. which was still not the right answer. Anyone see where I may have gone wrong?
 
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I don't see any mistakes. What did they give as the answer?
 
I didn't check your work on the pythagorean theorem. Otherwise, everything else looked fine to me... I'm scratching my head as well, except that the rocket sounds a bit heavy...

If you know the correct answer, perhaps the problem can be worked backward?
 
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