The Maths of Body Surfing
Ruben buy canada goose jacket Meerman: Nice waves! But have canada goose clearance you ever wondered why some people manage to catch them easily and others don’t, well there’s a science to surfing and I’m about to meet a mathematician whose thought about just that. G’day Neville!
Canada Goose online Professor Neville De canada goose uk black friday Mestre: G’day Ruben, how are you? Canada Goose online
Narration: Professor Neville De Mestre has been body surfing since he was a nipper. He’s canada goose uk shop won ten Canada Goose Online world surf masters events and thirty Australian masters surf championships. So if anyone knows about body surfing and wave dynamics its Professor Neville! Like a lot of people I’ve been body surfing for years. There’s not that much to it really or so I thought!
Professor De Mestre: Yes Ruben here comes one, let’s go for it
canadian goose jacket Narration: Unlike Professor Neville I certainly haven’t considered this in terms of a quantitative mathematical examination. canadian goose jacket
Canada Goose Jackets But it’s Canada Goose online worth considering some simple mathematical models for catching and riding a wave. Canada Goose Jackets
Canada Goose Outlet Professor De Mestre: That’s too early Ruben looks like it’s going to break on your head. Canada Goose Outlet
canada goose clearance Narration: There are definitely forces at work at work here canada goose clearance
canada goose clearance sale Professor De Mestre: I went to university and did a science degree and became interested in research into fluid mechanic’s and so I Canada Goose Coats On Sale really wanted to know canada goose clearance sale why a person could actually catch a wave and Canada Goose Parka ride it to canada goose coats on sale the beach. canada goose clearance sale
Narration: As part of his research Neville used small scale body surfer models, such as surfing barbie, to obtain an understanding of the physics involved.
canada goose black friday sale Ruben: Canada Goose Jackets Right so what does this mathematics you’ve been doing look like? canada goose black friday sale
canada goose coats on sale Professor De Mestre: Well the mathematics of body surfing depends on how fast the person Canada Goose Outlet can catch the wave and so it depends on Newton’s equations and if you remember newton equations where mass times acceleration of the body surfer, must be uk canada goose equal to in this case the propulsive force of the swimmer, canada goose coats plus the drag force due to the wave, that gives us a differential equation we can solve. canada goose coats on sale
Canada Goose sale Narration: Professor Neville de Mestre is Emeritus Professor uk canada goose outlet of Mathematics at Bond University on the Gold Coast and I’ve got a feeling canada goose factory sale this is about to get very complicated! Canada Goose sale
Professor De Mestre: Ruben this is a wave simulator machine and notice that the wave travels in this direction, what we’re interested in is what is the particle speed in the wave just at the front, just at the front here. Now if you’re swimming in a river and swimming upstream then the drags against you, you’ve got negative drag but if you’re swimming downstream and the rivers flowing faster than you can swim you’ve got positive drag, that’s what we’re interested in here we want positive drag from the wave front so that you can get buy canada goose jacket cheap up to wave speed and catch canada goose the wave.
Canada Goose Parka Ruben: Right so we need the assistance of that wave. That’s great but how about those equations? Canada Goose Parka
cheap Canada Goose Professor De Mestre: cheap Canada Goose Well let’s go and have a look at them. The mass of the swimmer, times the acceleration of the swimmer equals the propulsive force of the swimmer, plus the canada goose outlet drag. So let’s expand on this drag force for the wave. It’s proportional to the relative velocity squared now what’s the canada goose black friday sale relative velocity, well W is the speed of the wave particles and V is the speed of the swimmer and if you square it then that gives you cheap canada goose uk this expression. This now is a differential equation. The solution is V is equal to W minus A times something called the hyperbolic tan, it’s a very complicated mathematical expression and that involves this constant K, the time that we take off and the mass of the swimmer M. cheap Canada Goose
canada goose deals Ruben: Hang on a minute professor! What does all that actually mean? canada goose deals
buy canada goose jacket Professor De Mestre: From that we can work out whether the swimmer can actually catch the wave or not. buy canada goose jacket
canada goose coats Ruben: Canada Goose sale So the trick is we’ve got to get our speed up to wave speed. What kind of wave speed do we have to get up to in the ocean? canada goose coats
Professor De Mestre: The wave speed is three metres a second and swimmers like Grant Hackett and the Olympians do about two metres a second, most of us swim about http://www.canadagoosecanadaoutlet.com one metre a second, so we’ve got to increase our speed up to wave speed.
Narration: So if you’re a newcomer struggling to catch waves, start where it’s shallow and use your legs to push off, otherwise use flippers if you’re going out into deeper water. Now canadian goose jacket of course when you’re in the surf you’re not supposed to be thinking about a hyperbolic tan or the value of W, I’m sure my dolphin friends don’t but I’m very glad Professor Neville has!
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canada goose store G’day guys, has anyone listened to or read the story on Ockham’s Razor, which is linked just above? I haven’t yet, but there’s much more detail canada goose store.