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That would prove him wrong and I think he'd spontaneously combust!
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Right, that's the 200 up. Thanks very much everyone.
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i didn't do a-level english.
i could quote your o-level physics, but that would be betraying what i know. I know that if you throw a ball horizontally that it will hit the ground AFTER a ball dropped from the same point at the same time. I know that from experience, but like all good scientists i like to prove it. So I'll give it a go... I won't resort to links, that would be cowardly... but..., i've had a good think about this and i cannot actually work it out, because i suspect it is something a bit above a level physics. possibly part of my fluid dynamics course i did at uni 10 years ago involving reynolds' number etc. I apologise for this. But if i throw a tennis ball as hard as i can from shoulder height and drop one from shoulder height the one i throw will hit the ground last. this is quite simply a fact. |
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I'm thinking it is something to do with drag being related to speed as opposed to velocity. speed is a scalar whereas velocity is a vector, as is acceleration. i can't quite work it out just now. but drag (air resistance) is proportional to speed, not velocity or something like that. a shame i wasn't asked this question 10 years ago. hit ball obviously hits the ground last though.
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so where is your proof orioles?
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Not just that you'd throw it up in the air a bit, then?
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orioles 09 May 00:01
What did I do when I was bored BEFORE the Chit Chat forum? drink? |
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That is almost certainly not true, ironically. I suspect the action of air resistance would require a good deal of time in order to have a measurable effect. Merely throwing a ball would probably not be sufficient. As someone mentioned, I did this very experiment at school (because it is so counter-intuitive, it's a favourite of physics' teachers) and the ball-bearings did indeed hit the floor at the same time.
I have been pulling your leg, but I am genuinely astonished that you are not familiar enough with these principles to either convincingly confirm or deny my assertion. If I have upset you, I'm sorry, I was merely having some fun. None of us really knows each other and it's all nonsense in the end, but I do understand I can sometimes go too far. |
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i appreciate your last post. and i have to confess, when i'm in the mood, i can get rattled. even on chitchat. i'm not lying about my a-level results, though i realise i come across as a w.anker for mentioning them. just wound me up when you took the p.iiss and said I was lying about them for some reason. English obviously not one of my strong points. Anyway, when I was doing physics and maths and that i was always told not to accept stuff and work it out for yourself, and that is what i am trying to do. I DO know the old laws of motion of by heart and derivation(by calculus) and that, but i also know that if you throw a ball it will land after you drop one. Just couldn't quite work out how to prove it. Oh god, i'm making it even worse now. gonna go for a smoke i think.
take care orioles. |
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after you drop one??? i'm not quite so sure...have you met sparky?
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oi!
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Cheers, RD.
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hope to see you on one of my quiz threads soon orioles.
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This is a very interesting and fairly commonly asked question that does not have an easy answer.
To really get get to the crux of the matter you need to understand things like rotational velocity and additional concepts like the Magnus effect. However to end the argument - in a Null AV/Magnus neutral strike the struck golf ball hits the ground second. Good night. |
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I TRIED to tell them about the Magners effect...
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That is assumimg that the Earth is not rotating.
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coriolis force and oft forgotten force imo.
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Coriolus very useful for firing canonballs unless you sre on the eqautor when it does not make a difference
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how did this question generate 220 replies. they both have the same initial vertical velocity of zero and accelerate at 9.8m/s2 and so both hit the deck at the same time
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don't fkin start verdasco
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that true I droped a feather out the window when I was on the moon the other day and it hit the ground at the same time as the golf ball
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this was mechanics 1. not difficult really is it ;)
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OK - let's say Ronaldo is taking a free kick from a platform six feet above the ground.
Surely if he whacks it towards the goal it is going to be airborne way longer than if he just tips it over the edge? |
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not if it doesn't initially gain any height
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Verdasco I suspect you missed the riveting and exciting start of the tread where everyone knew the answer if you ssume nil air resistance.
There was an interesting aside about the golfball being hit at escape velocity and as well as this there was the question of what effect air resitnace will have. If I dont fall sleep I will see if I can ave a stab at that it might even help me drift off |
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i thought about air resistance for a bit honestnovice, but got confused. i think if i throw a ball from shoulder height and drop one from there at the same time the one i throw will hit the ground last. don't know how to prove it, realise it it counter intuitive etc, but sure the one i throw will hit the ground last. don't know how to prove it. drag proportional to speed, and that is as far as i got.
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isn't the horizontal velocity independent of the vertical. so would it not have the same drag as it dropped
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but drag is proportional to speed, not velocity. and speed is scalar not vector.
i'm not saying i've got the solution, but i am sure that is a large part of it. |
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I have just got back Roby and I know everyone accepts without air resistance resistance the two golf balls hit the earth at the same time excluding orbiting golf balls.
I read physics at university but ended up working fro a bank and certianly do not hold myself up as a fount of knowledge on the subject and suepct I have forgotten as much if not more then what I learnt in the first place. Out lecturers were very keen we did not accepts facts blindly and I rememeber once beeing told how people used to believe cannon balls fired at 45% or theraboute went straight for a while then stoped and fell to the earth. We all laughed as we "knew" they followed a parabela . The lecturer then took out a ballon and a tenis racket and hot the ballon at an angle of 45 degrees or therabout it went straight for a while then stoped and fell to earth. Apparently thats what cannon balls do as well to a close approxiamtion. The idea was dont acept the obvious I have spent 10 minutes on google for a "definitive" answer on this . If not I may try to modify the S=ut + 1/2 a*t*t by adding air resistance and see where the golf ball would be at time t if it is hit hrizonmtally at the terminal velocity of golf ball may at leat help me sleep l |
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ffs, this does not need 5 pages as orioles points out it is an "o" level physis question. They hit the ground at the same time.
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The o level answer is same time it is not the degree answer
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Well I have a Phd.
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that must be nice for you
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It is, as i know the anwser to things like this.
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So are you saying air resitance emakes no difference ?
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phd in anglo saxon?
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i realise this thread is all a bit of a p.iss take, but honest novice's point above is quite important. don't just accept what you consider to be the obvious answer, even if what you consider to be the obvious answer is also what you consider to be the smarter than the average answer.
I did think about it for a bit HN, but got stuck. Orioles just managed to hit a nerve with me (which is obviously his aim) and i got p.issed off. I never even had to learn those fkin laws of motion, i could just derive them or just use some kind of intuition. so i know that in theory they hit the ground at the same time, but in reality they don't. Was really racking my brains to work out a solution other than just saying "air resistance", will work it out one day i'm sure :) |
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Wel,l Naydam the Dense is very upset! There I was agreeing whole-heartedly with Orioles but I've been left on my own. He's gone and admitted that he was only kidding. Changed horses without even getting his feet wet! And there was me stikll tryinhg to picture whether or not the differential in atmospheric pressure between the top and the bottom of the ball would cause it to rotate.
So it looks like I was the only one to make the schoolboy error. Not to worry. I'm sure it won't be my last. :-) Damn! I wish I'd thought of the 'only kidding' excuse. :-( |
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Isn't it like walking in a straight line compared to a diagonal one?
The one fired from the cannon has to travel a longer distance to the ground. |
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oh god. i don't know who's taking the p.iss and who isn't now.
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