BravestDog 0 #1 September 1, 2012 1. Supposed you jumped off of a building, bridge, cliff, balloon...how many feet would you have to fall before you reach 120mph? Answer: "A typical skydiver in a spread-eagle position will reach terminal velocity after about 12 seconds, during which time they will have fallen around 450 m (approx 1,500 ft)." Found here: http://en.wikipedia.org/wiki/Free_fall under Examples. 2. People who jump from heights into pools, what are their speeds as they hit the water and how high are they jumping from? Are they reaching speed of 120mph? Answer: Dana Kunze, Record High Dive holder at 172 feet, tumbling type feet first entry. http://www.youtube.com/watch?v=4uHkyMh9FW4 Still looking for his speed at entry. Quote Share this post Link to post Share on other sites
Divalent 137 #2 September 1, 2012 You are asking for simple answers to non-simple questions (in this thread and others). You might want to review your HS (or college?) physics. You really would have a better understanding if you worked it out yourself. Here's a good place to start: http://en.wikipedia.org/wiki/Free_fall Quote Share this post Link to post Share on other sites
BravestDog 0 #3 September 1, 2012 I never took Physics in High School or College and am trying to research these questions that I've asked. Not trying to make things difficult, just asking some simple questions that pop up as I'm thinking about other posts that are somewhat related. Sometimes, the question if pretty simple. But when you get on Wikipedia, it becomes more complicated to the point where it's confusing, then I return to the forum looking for a simple answer. Just found the anwer: "A typical skydiver in a spread-eagle position will reach terminal velocity after about 12 seconds, during which time they will have fallen around 450 m (approx 1,500 ft)" at the Wikipedia Free Fall site. QuoteYou are asking for simple answers to non-simple questions (in this thread and others). You might want to review your HS (or college?) physics. You really would have a better understanding if you worked it out yourself. Here's a good place to start: http://en.wikipedia.org/wiki/Free_fall Quote Share this post Link to post Share on other sites
MasterMichael 1 #4 September 2, 2012 In the 1st second you will fall about 16 feet. At the two second mark you will have fallen about 64 feet. At the three second mark you will have fallen about 144 feet. At the four second mark you will have fallen about 256 feet. At the five second mark you will have fallen about 400 feet. I say "about" because I am not taking aerodynamic drag into account. At the start of your fall, the drag is not significant, As your velocity picks up, it starts to become more and more of a factor. The total distance (in feet) that you fall in a given number of seconds is about: 16 times the number of seconds times the number of seconds again. X = .5 x g x t^2 The velocity (in feet per second) would be about 32 times the number of seconds that you fall. Again that's not taking aerodynamic drag into consideration. V = g x t If you want to take drag into consideration, you need to know your coefficient of drag, and you need to know how to do calculus; or just look at the chart in Dan Poynter's book. Quote Share this post Link to post Share on other sites
godfrog 2 #5 September 2, 2012 QuoteIn the 1st second you will fall about 16 feet. At the two second mark you will have fallen about 64 feet. At the three second mark you will have fallen about 144 feet. At the four second mark you will have fallen about 256 feet. At the five second mark you will have fallen about 400 feet. I say "about" because I am not taking aerodynamic drag into account. ____________________________________________________________ Aside from simple drag you also have to consider mass and surface area. I.E. a pound of feathers and a pound of lead. At the start of your fall, the drag is not significant, As your velocity picks up, it starts to become more and more of a factor. The total distance (in feet) that you fall in a given number of seconds is about: 16 times the number of seconds times the number of seconds again. X = .5 x g x t^2 The velocity (in feet per second) would be about 32 times the number of seconds that you fall. Again that's not taking aerodynamic drag into consideration. V = g x t If you want to take drag into consideration, you need to know your coefficient of drag, and you need to know how to do calculus; or just look at the chart in Dan Poynter's book.Experience is a difficult teacher, she gives you the test first and the lesson afterward Quote Share this post Link to post Share on other sites
MasterMichael 1 #6 September 2, 2012 Yeah, yeah, yeah... You need your coefficient of drag, AND YOUR MASS (CALCULATED FROM YOUR WEIGHT OR VICE-VERSA REALLY), AND THE SQUARE FOOTAGE THAT'S EXPOSED TO THE AIR. AND take into account that the air density changes with your altitude. Quote Share this post Link to post Share on other sites
MasterMichael 1 #7 September 2, 2012 Here you go, if you're afflicted with skydiving, you might as well become afflicted with mathematics and science as well. It will give you something to do on rainy days. http://www.physicsforums.com/ Have fun :-D Quote Share this post Link to post Share on other sites
Idunno 0 #8 September 2, 2012 Quote2. People who jump from heights into pools, what are their speeds as they hit the water and how high are they jumping from? Are they reaching speed of 120mph? Answer: Dana Kunze, Record High Dive holder at 172 feet, tumbling type feet first entry. http://www.youtube.com/watch?v=4uHkyMh9FW4 Still looking for his speed at entry. From 172 feet he's falling about 60 mph. Quote Share this post Link to post Share on other sites
davelepka 4 #9 September 2, 2012 Let's not reply to this poster until he fills out his profile with a name and DZ where he jumps. All of his posts are asking basic questions that a real jumper might know, but some of the info is the type of stuff that would be of interest to a reporter or lawyer. Note that he signed up to DZ.com 9 years ago, but he's only asking very basic questions. Quote Share this post Link to post Share on other sites
piisfish 140 #10 September 2, 2012 The answer would be 42scissors beat paper, paper beat rock, rock beat wingsuit - KarlM Quote Share this post Link to post Share on other sites
kallend 2,027 #11 September 2, 2012 Quote In the 1st second you will fall about 16 feet. At the two second mark you will have fallen about 64 feet. At the three second mark you will have fallen about 144 feet. At the four second mark you will have fallen about 256 feet. At the five second mark you will have fallen about 400 feet. I say "about" because I am not taking aerodynamic drag into account. Well, we all know that terminal velocity has nothing to do with aerodynamic drag.... The only sure way to survive a canopy collision is not to have one. Quote Share this post Link to post Share on other sites
BravestDog 0 #12 September 3, 2012 Davelepka, I was hoping to ask some simple questions regarding Skydiving and want people to stay on topic without making False Accusations, Speculation and Comments that are Off Topic especially if it involves me, which it has. I'm not here to be your friend or to be popular. I don't need to know and have no desire to know who you are. I'm interested in asking some questions and learning something. My questions are on topic and relative to the forum. Would you politely remove your off topic posts to my questions before I contact the website administrator and have them do it for you? If that is necessary, then you will be wasting their time and my time because of YOUR inappropriate public behavior. If I wish to remain anonymous, guess what, it's NONE OF YOUR BUSINESS and it's probably a good idea. Ever hear of Identity Theft, Psychopaths, Sociopaths, Cyber Bullies, Mentally Ill Violent people who want to harm you etc? Guess what, they exist everywhere. Your responses are Off Topic, Accusatory, Speculatory and you are saying this in a public forum. Amounts to inappropriate behavior. If you feel the need to Speculate, Investigate, whatever...Use Private Messaging, your telephone and leave your responses out of my posts. I do not want you to post your responses to my questions if they are going to be off topic, accusatory and speculative Quote Let's not reply to this poster until he fills out his profile with a name and DZ where he jumps. All of his posts are asking basic questions that a real jumper might know, but some of the info is the type of stuff that would be of interest to a reporter or lawyer. Note that he signed up to DZ.com 9 years ago, but he's only asking very basic questions. Quote Share this post Link to post Share on other sites
petejones45 0 #13 September 3, 2012 Quote1. Supposed you jumped off of a building, bridge, cliff, balloon...how many feet would you have to fall before you reach 120mph? Answer: "A typical skydiver in a spread-eagle position will reach terminal velocity after about 12 seconds, during which time they will have fallen around 450 m (approx 1,500 ft)." Found here: http://en.wikipedia.org/wiki/Free_fall under Examples. 2. People who jump from heights into pools, what are their speeds as they hit the water and how high are they jumping from? Are they reaching speed of 120mph? Answer: Dana Kunze, Record High Dive holder at 172 feet, tumbling type feet first entry. http://www.youtube.com/watch?v=4uHkyMh9FW4 Still looking for his speed at entry. usually about 500Look out for the freefly team, Smelly Peppers. Once we get a couple years more experience we will be a force to be reckoned with in the near future! BLUES! Quote Share this post Link to post Share on other sites
petejones45 0 #14 September 3, 2012 Quote1. Supposed you jumped off of a building, bridge, cliff, balloon...how many feet would you have to fall before you reach 120mph? Answer: "A typical skydiver in a spread-eagle position will reach terminal velocity after about 12 seconds, during which time they will have fallen around 450 m (approx 1,500 ft)." Found here: http://en.wikipedia.org/wiki/Free_fall under Examples. 2. People who jump from heights into pools, what are their speeds as they hit the water and how high are they jumping from? Are they reaching speed of 120mph? Answer: Dana Kunze, Record High Dive holder at 172 feet, tumbling type feet first entry. http://www.youtube.com/watch?v=4uHkyMh9FW4 Still looking for his speed at entry. usually about 500Look out for the freefly team, Smelly Peppers. Once we get a couple years more experience we will be a force to be reckoned with in the near future! BLUES! Quote Share this post Link to post Share on other sites
dragon2 2 #15 September 3, 2012 [off-topic]That's funny [/off-topic] PS you might've meant to send him a PM. Although I appreciate the chuckle ciel bleu, Saskia Quote Share this post Link to post Share on other sites
RiggerLee 61 #16 September 3, 2012 I actually was going to post some thing relevent but this guy so sounds like a lawyer. Please add me to the list of people posting off topic comments in this thread. Please also insert apropreit derogatory comments and personal attacks here, ( __________ ). Thank you, LeeLee lee@velocitysportswear.com www.velocitysportswear.com Quote Share this post Link to post Share on other sites
dks13827 3 #17 September 3, 2012 Sorry for off topic... the posts above show the great difficulty of the calcs that NASA trajectory guys used to do !!! ( see: JPL, and of course, Space Shuttle and Apollo. ) Those guys were the big boys, the heavy weights !! :) Quote Share this post Link to post Share on other sites
CSpenceFLY 1 #18 September 3, 2012 QuoteDavelepka, I was hoping to ask some simple questions regarding Skydiving and want people to stay on topic without making False Accusations, Speculation and Comments that are Off Topic especially if it involves me, which it has. I'm not here to be your friend or to be popular. I don't need to know and have no desire to know who you are. I'm interested in asking some questions and learning something. My questions are on topic and relative to the forum. Would you politely remove your off topic posts to my questions before I contact the website administrator and have them do it for you? If that is necessary, then you will be wasting their time and my time because of YOUR inappropriate public behavior. If I wish to remain anonymous, guess what, it's NONE OF YOUR BUSINESS and it's probably a good idea. Ever hear of Identity Theft, Psychopaths, Sociopaths, Cyber Bullies, Mentally Ill Violent people who want to harm you etc? Guess what, they exist everywhere. Your responses are Off Topic, Accusatory, Speculatory and you are saying this in a public forum. Amounts to inappropriate behavior. If you feel the need to Speculate, Investigate, whatever...Use Private Messaging, your telephone and leave your responses out of my posts. I do not want you to post your responses to my questions if they are going to be off topic, accusatory and speculative Quote Let's not reply to this poster until he fills out his profile with a name and DZ where he jumps. All of his posts are asking basic questions that a real jumper might know, but some of the info is the type of stuff that would be of interest to a reporter or lawyer. Note that he signed up to DZ.com 9 years ago, but he's only asking very basic questions. You are funny as fuck. I hope someone somewhere likes you. Quote Share this post Link to post Share on other sites
Andy9o8 2 #19 September 3, 2012 QuoteHow many feet would you have to fall to reach 120mph? I think the real question is not how many feet, but how many hands. Quote Share this post Link to post Share on other sites
chutem 0 #20 September 3, 2012 QuoteQuoteHow many feet would you have to fall to reach 120mph? I think the real question is not how many feet, but how many hands. 3 times as many as feet. Quote Share this post Link to post Share on other sites
Andy9o8 2 #21 September 3, 2012 QuoteIf I wish to remain anonymous, guess what, it's NONE OF YOUR BUSINESS and it's probably a good idea. Ever hear of Identity Theft, Psychopaths, Sociopaths, Cyber Bullies, Mentally Ill Violent people who want to harm you etc? Guess what, they exist everywhere. Your responses are Off Topic, Accusatory, Speculatory and you are saying this in a public forum. Amounts to inappropriate behavior. If you feel the need to Speculate, Investigate, whatever...Use Private Messaging, your telephone and leave your responses out of my posts. I do not want you to post your responses to my questions if they are going to be off topic, accusatory and speculative BWAHAHAHAHA. How many times did you fail the bar exam? BWAHAHAHAHAAA. Quote Share this post Link to post Share on other sites
Amazon 7 #22 September 3, 2012 QuoteQuoteIf I wish to remain anonymous, guess what, it's NONE OF YOUR BUSINESS and it's probably a good idea. Ever hear of Identity Theft, Psychopaths, Sociopaths, Cyber Bullies, Mentally Ill Violent people who want to harm you etc? Guess what, they exist everywhere. Your responses are Off Topic, Accusatory, Speculatory and you are saying this in a public forum. Amounts to inappropriate behavior. If you feel the need to Speculate, Investigate, whatever...Use Private Messaging, your telephone and leave your responses out of my posts. I do not want you to post your responses to my questions if they are going to be off topic, accusatory and speculative BWAHAHAHAHA. How many times did you fail the bar exam? BWAHAHAHAHAAA. Careful Andy.... useage of that sort of chortling is apparently a bannable offense. Quote Share this post Link to post Share on other sites
MasterMichael 1 #23 September 3, 2012 Well, if he's a lawyer he will know the answer to this question: Q. If a criminal lawyer, a civil lawyer, and a divorce lawyer all jump out of an airplane at the same time with no parachutes, which one will hit the ground first? A. Who gives a S**t. Quote Share this post Link to post Share on other sites
richardw38 0 #24 September 3, 2012 so I'm doing a FF course in a couple of weeks, can I use my RW suit? Quote Share this post Link to post Share on other sites
Scrumpot 1 #25 September 3, 2012 Quote How many times did you fail the bar exam? Do you want a "Speculatory" guess? Great thread(s)! coitus non circum - Moab Stone Quote Share this post Link to post Share on other sites
