 Poster: A snowHead
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Obviously A snowHead isn't a real person
Obviously A snowHead isn't a real person
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Somehow I still remembered my GSE physics and managed to get the right answer.
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Well, the person's real but it's just a made up name, see?
Well, the person's real but it's just a made up name, see?
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It says "Ignore wind resistance" but obviously the skier isn't. He's down in a decent tuck, and his chin is cutting through the air nicely!
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You need to Login to know who's really who.
You need to Login to know who's really who.
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no idea.
i'm so bad at maths!
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Anyway, snowHeads is much more fun if you do.
Anyway, snowHeads is much more fun if you do.
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If the slope is frictionless, then why does the skier require an upward movement to get moving?
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You'll need to Register first of course.
You'll need to Register first of course.
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In addition, it doesnt look much like the skier is accelerating at all!
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crazy_skier_jules,
speed = distance / time
so
time skier travelled = vertical distance / average speed of skier
av speed = time x 9.8 (acceln due to gravity) x 0.5 (as halfway between zero and max speed)
so
time skier travelled = vert d / time x 9.8 x 0.5
so
time squared = vert d / 9.8 x 0.5
max speed then is time x 9.8
eg 30metres / 4.9msec^2 = 6.12sec^2
root of 6.12sec^2 = 2.47 seconds
max speed = 2.47sec x 9.8msec^2 = 24.25m/sec
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You'll get to see more forums and be part of the best ski club on the net.
You'll get to see more forums and be part of the best ski club on the net.
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Ian Hopkinson, for someone who's not good at maths?! Prefer mine, mate! 
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slikedges, the one that works for you is the best one
Guess how much someone was charging for a weekend coaching for Oxbridge entry ?
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snowHeads are a friendly bunch.
snowHeads are a friendly bunch.
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Ian Hopkinson, both work for me. But I'm guessing mine might be easier for someone less good at scientific and mathematical abstraction to follow. Might be wrong.
Go on then...it's bound to be astronomical! <waits with bated breath>
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And love to help out and answer questions and of course, read each other's snow reports.
And love to help out and answer questions and of course, read each other's snow reports.
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£840! - includes accommodation in a Moat House Hotel 
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Ian Hopkinson, for that I'd expect them to provide a microtransmitter and microreceiver! How much were you able to teach them? 
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You know it makes sense.
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slikedges, can't really see it being money well spent...
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Otherwise you'll just go on seeing the one name:
Otherwise you'll just go on seeing the one name:
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| slikedges wrote: |
| Ian Hopkinson, for someone who's not good at maths?! Prefer mine, mate! |
I am not sure yours is right though! The web page says its incorrect. As Ian pointed out, converting the gravitation engery into kinentic energy you get:
0.5mv^2 = mgh
0.5 v^2 = gh
v^2 = 2gh = 2*9.81* 72 = 1412.64
v = 37.59m/s (which website says is correct)
The difference is because you are assuming that your skier is accelerating at a rate of g in the line of the slope which isn't correct. You need to bring in some trig into your answer to make it correct.
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Poster: A snowHead
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kamikaze, the two equations say exactly the same thing, just expressed with the same terms in different places. Promise.
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Obviously A snowHead isn't a real person
Obviously A snowHead isn't a real person
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kamikaze, the reason that slikedges gives the wrong answer is that in his example he didn't use the height from the question. The height is 52m, for some reason, slikedges quoted 30m. His does work if you use the correct height.
btw, I think you mis-typed the height in yours - it should be 52, not 72. 
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Well, the person's real but it's just a made up name, see?
Well, the person's real but it's just a made up name, see?
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kamikaze, Ray Zorro, the height in the question changes each time.
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You need to Login to know who's really who.
You need to Login to know who's really who.
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All I get is "The page canot be displayed" on the links. What am I doing wrong?
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Anyway, snowHeads is much more fun if you do.
Anyway, snowHeads is much more fun if you do.
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Dunno. I just clicked on the links.
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You'll need to Register first of course.
You'll need to Register first of course.
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Alan, try the second link - the first one just gives me gibberish as well.
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Neither will open in IE, Firefox says "Operation Timed Out when trying to contact .....blah blah". Oh well, it was probably too difficult for me anyway. I see the mediazone is back on line slikedges 
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Alan Craggs, odd. I'm running IE6. Haven't tried in Opera or Firefox.
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You'll get to see more forums and be part of the best ski club on the net.
You'll get to see more forums and be part of the best ski club on the net.
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kamikaze, slikedge's answer is also right. The way he has written it implies a cliff jump rather than a schuss down a slope, but because there is no friction the two situations are equivalent.
Wear The Fox Hat, I hadn't noticed that...but you're right, maybe he was excited and decided to jump into the air, before realising the seriousness of his situation
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