acceleration of gravity
-
because the thread apparently got deleted (why?) before i was able to look at it today, i'm going to start a new one
nate's reply
The resistance from air or anything else would be negligible at this slow of speed. >His terminal velocity, from a 50ft fall, would be 38.7mph as adog said. I don't know >about you, but I wouldn't want to run into something that is stopped at 38.7mph >with only a helmet protecting me.
out there, what the heck is 5m/s/s? I think you meant, 5 m/s^2?
the acceleration of gravity is 9.8 meters per second per second (m/s/s is a common abbreviation); however, the air resistance of a body and the clothing on said body would likely cause it to fall at a slower rate. i'm just guessing at how much slower it would fall, but based on the numbers chuck posted about terminal velocity (spread eagle vs headfirst), i think i was being kind of generous in only reducing the rate by about 50%
at 5m/s/s, a body would fall 16.4ft in the first second and accelerate to 11.2mph, then fall an additional 32.8ft in the next second, accelerating to 22.4mph, and that's roughly the distance from start to stop.
because the air resistance is so small at a speed this low, i assumed constant acceleration, which is probably as silly as this thread
-
there is a reason why it got deleted, it is very very disrespectful to talk about people like this, you should not be trying to figure out how fast he fell. Im sorry if i come off like an ass, but its not cool at all.
One of my friends got hit in the face with a golf ball(from 20ft away or closer at the tee box) on monday and it shattered his nose and cheek bone. He almost lost his vission due to it hitting his eye, and if the ball would have hit him square in the eye and not the cheek bone/nose, he would be dead. Sure it sounds funny because he got hit in the face with a golf ball and almost died, but it is disrespectful to laugh.
I hate people who laugh and try and figure stuff out like how fast someone was falling just due to the disrespect. I have had many friends in the hospital later to die so i just cant stand the disrespect.
END RANT...
-
Yeah I think you made some people mad.
-
ok, so i should feel bad for other people being offended?
explain what kind of disrespect i showed this person?
how dare i use the event of a person falling from a bridge to spark an intellectual discussion. there are so many things that i would like to say in response to that thread being deleted, but i don't know where to begin.
harwood- rant all you want about your anecdotal justification for being unhappy with what i post, it doesn't bother me. do i care that your friend was hit by a golf ball? no, does it irk you that i just posted that? i know it does, so don't try to lie to yourself. do i care? no, why should i be sorry? i wasn't involved, and the likelihood of said event having an impact on my life is almost zero.
your obvious response is "what if that happened to you?" ok, so i get hit in the face with a golf ball, i get on with my life. newsflash folks, i've been there. i fell asleep on the interstate with an suv full of music equipment and then hit a culvert ramp thing in the median. somehow the highway patrol found out about the crash and paramedics arrived like 4 hours later. i spent three days in a coma because my brain was hemorhaging, my lung was bruised, a couple of ribs were cracked, and had pneumonia on top of it all... totalling a week in the hospital and another few weeks off of work (doctors recommended a couple months). had i been in the wrecked vehicle for another 4-6hours (some number less than a day) i probably would have died.
do i expect any of you to care about my incident? no, that would be silly, just as silly as you overreacting about me taking the motorcycle accident lightly.
am i saying that i don't feel bad about horrible things happening to people? you bet.
whack big slap to the face there
why should any "traumatic" event involving other people bother me? if i was emotionally shaken at every gruesome event, i wouldn't be able to go on with life due to the vast number of occurences.
do you have anything else that i need to address? or have i defended myself effectively?for those of you that actually read this far, (chuck, wes, jared, blake? anyone else?) i could have written this in a much friendlier and positive way... but would it have had the same effect? consider the audience and then tell me what you think
-
very well said. ^
personally, i dont see how figuring out how he fell is disrespecful. the discussion wasnt conducted in an immature manner. (like "hahahaha. he fell off the bridge at 22.4mph! sucks for him!! baaahahahah.") so why all the fuss? like adam said, if we were shaken at every traumatic event in life, we wouldnt be able to go on. applying science to a tragic event only helps us better learn about it.
i can say for an absolute certainty there was no intentional disrespect in the original discussion.
-
I saw footage of my friend getting shot yesterday with a shotgun. That was actually hilarious.
I'll post it later.
-
i wish i had footage of my friend getting hit in face with the golf ball, cause he fell backwards like a board and was unconsious for a while.
I didnt mean to come off like an ass, cause personally i laugh about everything that happens to me. But i konw some people dont like to be talked about like that.
-
out there wrote:
because the thread apparently got deleted (why?) before i was able to look at it today, i'm going to start a new onenate's reply
The resistance from air or anything else would be negligible at this slow of speed. >His terminal velocity, from a 50ft fall, would be 38.7mph as adog said. I don't know >about you, but I wouldn't want to run into something that is stopped at 38.7mph >with only a helmet protecting me.
out there, what the heck is 5m/s/s? I think you meant, 5 m/s^2?
the acceleration of gravity is 9.8 meters per second per second (m/s/s is a common abbreviation); however, the air resistance of a body and the clothing on said body would likely cause it to fall at a slower rate. i'm just guessing at how much slower it would fall, but based on the numbers chuck posted about terminal velocity (spread eagle vs headfirst), i think i was being kind of generous in only reducing the rate by about 50%
at 5m/s/s, a body would fall 16.4ft in the first second and accelerate to 11.2mph, then fall an additional 32.8ft in the next second, accelerating to 22.4mph, and that's roughly the distance from start to stop.
because the air resistance is so small at a speed this low, i assumed constant acceleration, which is probably as silly as this threadNo, the acceleration of gravity is 9.8 m/s^2, have you ever had a physics class? Do you understand what acceleration is? Your abbreviation is retarded, m/s/s would simply equal to m, the seconds would cancel each other. You can't just modify the force of gravity. Gravity will be applying a force of acceleration to an object at 9.8m/s^2 no matter what (or about 32.2ft/s^2). You can't just say, oh, this object will have this much air resistance, lets just lower the force of gravity to estimate it. The air resistance would be pretty small going from a stop to ~40 mph, you can ignore it.
Adam (I think that is who it was) and I were correct, it would be about 38.7mph from a 50ft fall. Granted, there would be a small amount of air resistance once the object got some speed, but with the speeds we are dealing with, it is negligible. If we all really care that much, I can calculate the actual resistance from the air, and give us a real close answer. I am pretty lazy right now though.
Maybe you should stick to delivering pizza?
-
91nbtsi wrote:
No, the acceleration of gravity is 9.8 m/s^2, have you ever had a physics class? Do you understand what acceleration is? Your abbreviation is retarded, m/s/s would simply equal to m, the seconds would cancel each other. You can't just modify the force of gravity. Gravity will be applying a force of acceleration to an object at 9.8m/s^2 no matter what (or about 32.2ft/s^2). You can't just say, oh, this object will have this much air resistance, lets just lower the force of gravity to estimate it. The air resistance would be pretty small going from a stop to ~40 mph, you can ignore it.Adam (I think that is who it was) and I were correct, it would be about 38.7mph from a 50ft fall. Granted, there would be a small amount of air resistance once the object got some speed, but with the speeds we are dealing with, it is negligible. If we all really care that much, I can calculate the actual resistance from the air, and give us a real close answer. I am pretty lazy right now though.
Maybe you should stick to delivering pizza?
the other thing to keep in mind is that you don't instantly reach terminal velocity, so you are in fact going slower than 9.8 m/s^2 if you "only" fall 50 feet. I forget how far you need to fall before you reach terminal velocity, but I believe it is over 100 feet...I could be wrong.
-
i know what the acceleration of gravity is
http://www.glenbrook.k12.il.us/gbssci/phys/Class/1DKin/U1L5b.html
http://www.homepage.montana.edu/~uessc/esci450/RamCalculations.html
http://www.physicsclassroom.com/Class/1DKin/U1L5a.html
i wasn't sure how to abbreviate the acceleration of gravity, so i looked it up, hence the reason i said that "m/s/s is a common way to abbreviate it"
i was guessing that with the size of a body and the clothing on it, it's acceleration would be reduced. i understand that gravity is a constant, but i also understand that acceleration isn't.
i know that you have much more understanding about this stuff than i do, but at the same time, you are too concrete with theoretical numbers. after watching some footage of things of various sizes falling short distances, i was way too far off with reducing acceleration to 5. -
out there wrote:
i know what the acceleration of gravity is
http://www.glenbrook.k12.il.us/gbssci/phys/Class/1DKin/U1L5b.html
http://www.homepage.montana.edu/~uessc/esci450/RamCalculations.html
http://www.physicsclassroom.com/Class/1DKin/U1L5a.html
i wasn't sure how to abbreviate the acceleration of gravity, so i looked it up, hence the reason i said that "m/s/s is a common way to abbreviate it"
i was guessing that with the size of a body and the clothing on it, it's acceleration would be reduced. i understand that gravity is a constant, but i also understand that acceleration isn't.
i know that you have much more understanding about this stuff than i do, but at the same time, you are too concrete with theoretical numbers. after watching some footage of things of various sizes falling short distances, i was way too far off with reducing acceleration to 5.Acceleration on a free falling body is constant. Velocity and the force from air resistance are dependant on acceleration,time, etc.. Why am I too concrete? The force of gravity is concrete..:)
tjamz wrote:
the other thing to keep in mind is that you don't instantly reach terminal velocity, so you are in fact going slower than 9.8 m/s^2 if you "only" fall 50 feet. I forget how far you need to fall before you reach terminal velocity, but I believe it is over 100 feet...I could be wrong.huh? 9.8m/s^2 is the force or acceleration on a free falling object, it is not a rate or speed. I think you might be confusing a few things. The 9.8m/s^2 force is present at all times, whether the object is in motion, or just sitting there. Even on all your lazy asses that are reading this have a 9.8m/s^2 acceleration force pushing down on you right now, hence why your ass is getting sore. You are right, the "body" or person in this case, is not going to reach terminal velocity in 50ft, the the acceleration on that body is the same the whole way down. What terminal velocity is, is when the resistance force from air and any other resistance the object encounters while falling is EQUAL to the force of gravity on the object.
Hello! It looks like you're interested in this conversation, but you don't have an account yet.
Getting fed up of having to scroll through the same posts each visit? When you register for an account, you'll always come back to exactly where you were before, and choose to be notified of new replies (either via email, or push notification). You'll also be able to save bookmarks and upvote posts to show your appreciation to other community members.
With your input, this post could be even better 💗
Register Login