October 30, 201411 yr [ATTACH=CONFIG]47620[/ATTACH] This reminds me of ..... sorry, going off subject alert!!!... I watch a silly show called Below Deck, one of those reality shows. It's about a crew of a yacht and it video tapes them during an entire season of charters etc. The Head Stew had a disablity that never came out during the show until the end when they did one of those season re-cap shows. She had a disability and it was she didn't have the sense of smell. No ability to smell anything. I was thinking how kind of awful that would be not to be able to smell some things, but then I thought, and your picture is a great example of it...the elephant house at the zoon wouldn't be so bad after all.
October 30, 201411 yr A key variable here is the distance from the plane to one of us standing in the desert. Since you mentioned that the plane was only several HUNDRED feet off the ground, the short distance would lead to a short triangular (think of a boat's wake), so the boom would be heard very shortly behind the jet, and it would be LOUD.
October 30, 201411 yr While Big V is avoiding some responses in this thread I have a couple of other questions for anyone in the know. 1. How fast do sonic boom sound waves move? The speed of sound or something else? I know it sounds like a stupid question but that is okay. 2. The original sonic boom would have taken place around 1500 miles away, how much does sound dissipate over distance keeping in mind a dessert is somewhat consistent terrain? 1) Speed of sound. In the air, that speed changes depending on temperature and humidity. In school, that number was almost always given as part of the problem. Something like 320 m/s or 340 m/s. 2) It dissipates a lot. I can't imagine you'd hear much of anything that happened 1,500 miles away. No matter what, even if that sound could get to you, you'd still see the plane a long time before hand because it's traveling considerably faster than the sound wave. If the plane was only a few hundred feet overhead, it wouldn't be immediate because the boom basically generates in a cone behind the airplane (which is traveling faster than the sound wave), but it would be pretty darn close.
October 30, 201411 yr 1) Speed of sound. In the air, that speed changes depending on temperature and humidity. In school, that number was almost always given as part of the problem. Something like 320 m/s or 340 m/s. 2) It dissipates a lot. I can't imagine you'd hear much of anything that happened 1,500 miles away. No matter what, even if that sound could get to you, you'd still see the plane a long time before hand because it's traveling considerably faster than the sound wave. If the plane was only a few hundred feet overhead, it wouldn't be immediate because the boom basically generates in a cone behind the airplane (which is traveling faster than the sound wave), but it would be pretty darn close. Good answer, good answer!
October 30, 201411 yr 1) Speed of sound. In the air, that speed changes depending on temperature and humidity. In school, that number was almost always given as part of the problem. Something like 320 m/s or 340 m/s. 2) It dissipates a lot. I can't imagine you'd hear much of anything that happened 1,500 miles away. No matter what, even if that sound could get to you, you'd still see the plane a long time before hand because it's traveling considerably faster than the sound wave. If the plane was only a few hundred feet overhead, it wouldn't be immediate because the boom basically generates in a cone behind the airplane (which is traveling faster than the sound wave), but it would be pretty darn close. Thanks Getslow, I love hanging out with smart people. On the cone behind the plane, are you saying you would hear the boom because it travels "with" the plane? Thus there would be "multiple booms" as the lines between time and space blur? Or are you saying we would hear the plane almost immediately and nothing about the original boom?
October 30, 201411 yr Ya'll are way too smart for me. There are some seriously impressive nerds on here.
October 30, 201411 yr Author You need to know how long it took for the plane to accelerate from Mach 1 up to Mach 2 in order to properly answer. Reason being, as soon as the plane surpasses the speed of sound (call it 761.21 mph), it begins to separate itself from the sound wave it has created, and it continues to increase that separation at an increasing rate until it levels off its speed after reaching Mach 2. Think of it this way: Scenario 1 You are driving next to another car, and you are both traveling at 60mph. The other car maintains its 60mph speed while you speed up to 75mph and travel at that speed for 9 minutes 45 seconds before eventually increasing your speed up to 80mph. It takes you 15 seconds to increase speed from 75mph to 80 mph. So in the course of 10 minutes you have increased your speed by 20mph. However, you were traveling at 75 mph for the majority of those 10 minutes, all while the other car maintained a constant 60mph and you pulled away from it. Scenario 2 You are driving next to another car, and you are both traveling at 60mph. The other car maintains its 60mph speed while you speed up to 65mph and travel at that speed for 9 minutes 45 seconds before eventually punching it up to 80mph. It takes you 15 seconds to increase speed to 80 mph. So in the course of 10 minutes you have increased your speed by 20mph, but you were only going 65 mph for the majority of those 10 minutes. Again, the other car maintained its constand 60mph speed as you pulled away from it further. You can see how the distance between the two cars at the end of the 10 minute periods in the scenarios would be larger in Scenario 1 than it would be in Scenario 2, can't you? That's why in your original question regarding the plane and the speed of sound you would need to know how long it took to move from Mach 1 to Mach 2. To the bolded, if the plane had been going Mach 2 for 1 hour and held that constant velocity, that should suffice to answer that correct?
October 30, 201411 yr Thanks Getslow, I love hanging out with smart people. On the cone behind the plane, are you saying you would hear the boom because it travels "with" the plane? Thus there would be "multiple booms" as the lines between time and space blur? Not really; the noise is continuous. It travels with the plane in that the sound is generated by the nose of the plane creating pressure waves in the air in front of it. I'll try to find a picture.
October 30, 201411 yr Author 1) Speed of sound. In the air, that speed changes depending on temperature and humidity. In school, that number was almost always given as part of the problem. Something like 320 m/s or 340 m/s. 2) It dissipates a lot. I can't imagine you'd hear much of anything that happened 1,500 miles away. No matter what, even if that sound could get to you, you'd still see the plane a long time before hand because it's traveling considerably faster than the sound wave. If the plane was only a few hundred feet overhead, it wouldn't be immediate because the boom basically generates in a cone behind the airplane (which is traveling faster than the sound wave), but it would be pretty darn close. 1. Which is why I said in my op lets ASSUME 761.2 is the speed of sound in this scenario because it is dependent upon other varying factors. 2. Which is why I had the plane only a few hundred feet overhead, when the sound did get there I wanted it to be heard.
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