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| | For over a decade, the Prostate Cancer Education Council (PCEC) has provided free plus low-cost screenings to men during the third week of September, called Prostate Cancer Awareness Week (PCAW).<br><br>Why a male swimmer's body is really sexy is considering they have low body fat ratio thus that their perfectly toned muscles could be enjoyed and not covered by too much body fat. Although low in body fat, swimmers body fat ratio are not because low because pro bodybuilders throughout competition whose bodies have veins popping out with ripped railway track definitions. The swimmer's body is defined by Wisegeek because a high level of muscle tone with a lack of bulk and is a universally appealing body form.<br><br>When you think of fats, we assume they are anything to be avoided waist to height ratio. This is not true. In truth, fats are required for the absorption of certain vitamins (A, D, E, plus K which are recognised as "fat soluble vitamins") plus work other functions inside the metabolism of foods. Let's clear up the confusion about dietary fats.<br><br>This sounds perplexing, thus I'll clear it up. I'm a licensed individual trainer. Body mass index (BMI), is a measurement of body fat based on height and weight. Normal weight is a value of 18.5 to 24.9; overweight is 25 to 29.9, plus obese is 30 plus above.<br><br>These types of results are not distinctive to MacMasters. Dr David Heber, Ph.D., from UCLA's Centre for Human Nutrition reports which distribution of body fat is a more important predictor of heart attack risk than the conventional measurement of Body Mass Index (BMI), that is a measurement based on the ratio between the height plus weight.<br><br>Underwater Weighing - Underwater weighing, or hydrostatic weighing, is another way to determine the body fat . In this procedure, a person sits inside a specialized seat, expels the air from their lungs, and [http://safedietplansforwomen.com/waist-to-height-ratio waist to height ratio] is then submerged into a big steel tank of water to remain motionless whilst their underwater weight is recorded. This is repeated till a dependable fat is calculated. The purpose is to measure density of the body plus calculate yourfat weight. Because lean tissue is denser than fat tissue, this way may determine the buoyancy of a individual while underwater. When considered the gold standard offat measuring, the equipment is quite costly, creating other methods more attractive.<br><br>The perfect waist size will be between 45%-47% of the height. In other words, if you're 70 inches tall you're perfect waist is between 31.5 - 33 inches.<br><br>It is significant to be aware of your body in order to have a healthy body image, however, not too aware. Having certain fat on a body is not a bad thing, only the lack of fat or the excessive presence of fat is what can be dangerous to the health. Use the wellness resources available online as a reference to see if you're keeping the body healthy. |
| [[Image:DiagramApparentWind.gif|thumb|325px|V = boat speed, H = head wind, W = true wind, A = apparent wind, α = pointing angle, β = angle of apparent wind]]
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| '''Apparent wind''' is the wind experienced by a moving object.
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| ==Definition of apparent wind==
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| The ''Apparent wind'' is the wind experienced by an observer in motion and is the [[relative velocity]] of the wind in relation to the observer.
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| ''Apparent wind'' [[velocity]] is the [[vector sum]] of the ''true wind'' and the headwind an object would experience in still air. The headwind velocity in still air is [[Additive inverse|inverse]] of the object's velocity, therefore the apparent wind can also be defined as a vector subtraction: the '''''Velocity of the wind''' minus the '''Velocity of the object'''''. | |
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| ==A simple example==
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| Suppose you are riding a bicycle on a day when there is no wind. Although the wind speed is zero (people sitting still feel no breeze), you will feel a breeze on the bicycle due to the fact that you are moving through the air. This is the apparent wind. On the windless day, the apparent wind will always be directly in front and equal in speed to the speed of the bicycle.
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| Now suppose there is a 5 mph wind coming directly from the north. If you pedal at 10 mph due north, you will feel an apparent wind of 15 mph from the north. But if you pedal 10 mph due south, you will feel an apparent wind of 5 mph from the south. The apparent wind is not only different in speed than the true wind (except when you are standing still), but may also be different in direction.
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| In these simple examples, the motion is parallel to the true wind which makes it easy to calculate the speed and direction of the apparent wind in relation to true wind speed (relative to the earth). When the motion is not parallel to the wind, one must use trigonometry to calculate the apparent wind. Vector mathematics might also be useful in some cases.
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| ==Apparent wind in sailing==
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| In [[sailing]], the apparent wind is the actual flow of air acting upon a [[sail]]. It is the wind as it appears to the sailor on a moving vessel.
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| It differs in speed and direction from the '''true wind''' that is experienced by a stationary observer.
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| In [[nautical terminology]], these properties of the ''apparent wind'' are normally expressed in [[Knot (unit)|knots]] and [[degree (angle)|degree]]s.
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| ==Calculating velocity and angle==
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| <math>A = \sqrt{W^2 + V^2 +2WV\cos{\alpha}}</math> | |
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| Where:
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| * <math>V</math> = velocity (boat speed over ground, always > 0)
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| * <math>W</math> = true wind velocity (always > 0)
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| * <math>\alpha</math> = true pointing angle in degrees (0 = upwind, 180 = downwind)
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| * <math>A</math> = apparent wind velocity (always > 0)
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| The above formula is derived from the [[Law of cosines]] and using <math>\cos(\alpha') = \cos(180 \text{º}-\alpha) = -\cos(\alpha)</math>.
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| The angle of apparent wind (<math>\beta</math>) can be calculated from the measured velocity of the boat and wind using the inverse cosine in degrees (<math>\arccos</math>)
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| <math> \beta = \arccos \left( \frac{W\cos \alpha+V}{A} \right) = \arccos \left( \frac{W\cos \alpha+V}{\sqrt{W^2 + V^2 +2WV\cos{\alpha}}} \right)</math>
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| If the velocity of the boat and the velocity and the angle of the apparent wind are known, for instance from a [[Apparent wind#Instruments|measurement]], the true wind velocity and direction can be calculated with:
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| <math>W = \sqrt{A^2 + V^2 - 2AV\cos{\beta}}</math> | |
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| and
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| <math> \alpha = \arccos \left( \frac{A\cos \beta-V}{W} \right) = \arccos \left( \frac{A\cos \beta-V}{\sqrt{A^2 + V^2 -2AV\cos{\beta}}} \right)</math>
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| ==Instruments==
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| The '''apparent wind''' on-board is often quoted as a speed measured by a [[Mast (sailing)|masthead]] [[transducer]] containing an [[anemometer]] and [[Weather vane|wind vane]] that measures wind speed in [[Knot (unit)|knots]] and wind direction in degrees relative to the [[Course (navigation)|heading]] of the boat. Modern instrumentation can calculate the true wind velocity when the apparent wind and boat velocity are input.
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| ==Implications on sailing speeds==
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| In [[sailboat racing]], and especially in [[speed sailing]], apparent wind is a vital factor, when determining the [[points of sail]] a sail-boat can effectively travel in. | |
| A vessel traveling at increasing speed relative to the ''prevailing wind'' will encounter the wind driving the sail at a decreasing angle and increasing velocity. Eventually, the increased drag and diminished degree of efficiency of a sail at extremely low [[Angle of attack|angles]] will cause a loss of accelerating force. This constitutes the main limitation to the speed of wind-driven vessels and vehicles.
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| [[windsurfing|Windsurfers]] and certain types of boats are able to sail faster than the true wind. These include fast [[multihull]]s and some [[Planing (sailing)|planing]] monohulls. [[ice yachting|Ice-sailors]] and [[land sailing|land-sailors]] also usually fall into this category, because of their relatively low amount of [[drag (physics)|drag]] or [[friction]].
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| In the foiling AC72 America's cup catamarans,the boats sail through the water at up to double the environmental wind strength. The effect of this is to radically change the apparent wind direction when sailing "downwind". In these boats the forward speed is so great that the apparent wind is always forward-at an angle that varies between 2 and 4 degrees to the wing sail. This means that AC72's are effectively tacking downwind, although at a greater angle than the normal 45 degree upwind angle,usually between 50 and 70 degrees.<ref>TVNZ Live America's cup Broadcast.Interview with Tom Schnackenburg. 22/9/2013</ref>
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| ==Other areas of relevance==
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| In [[fixed-wing aircraft]], apparent wind is what is experienced on-board and it determines the necessary speeds for take-off and landing. [[Aircraft carrier]]s generally steam directly upwind at maximum speed, in order to increase apparent wind and reduce the necessary take-off velocity. Land-based [[airport]] traffic, as well as most mid-sized and large birds generally take off and land facing upwind for the same reason. | |
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| ==Online calculation and graphical impact presentation ==
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| [http://web.me.com/cscholiers/Wind_%26_Apparent_Wind/True_and_Apparent_Wind.html Short introduction related to Kitebuggy, Kite-MTB, Kitesurf]<br />
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| [http://www.starpath.com/freeware/true_wind.htm Input Wind speed & Course in degrees and Course speed, as an input to calculate apparent wind speed and apparent wind angle]
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| ==References==
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| {{reflist}}
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| == External links ==
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| * [http://sites.google.com/site/navigationalalgorithms/ Navigational Algorithms] Apparent wind soft, math: vector solution, and examples.
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| {{DEFAULTSORT:Apparent Wind}}
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| [[Category:Sailing]]
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| [[Category:Navigation]]
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For over a decade, the Prostate Cancer Education Council (PCEC) has provided free plus low-cost screenings to men during the third week of September, called Prostate Cancer Awareness Week (PCAW).
Why a male swimmer's body is really sexy is considering they have low body fat ratio thus that their perfectly toned muscles could be enjoyed and not covered by too much body fat. Although low in body fat, swimmers body fat ratio are not because low because pro bodybuilders throughout competition whose bodies have veins popping out with ripped railway track definitions. The swimmer's body is defined by Wisegeek because a high level of muscle tone with a lack of bulk and is a universally appealing body form.
When you think of fats, we assume they are anything to be avoided waist to height ratio. This is not true. In truth, fats are required for the absorption of certain vitamins (A, D, E, plus K which are recognised as "fat soluble vitamins") plus work other functions inside the metabolism of foods. Let's clear up the confusion about dietary fats.
This sounds perplexing, thus I'll clear it up. I'm a licensed individual trainer. Body mass index (BMI), is a measurement of body fat based on height and weight. Normal weight is a value of 18.5 to 24.9; overweight is 25 to 29.9, plus obese is 30 plus above.
These types of results are not distinctive to MacMasters. Dr David Heber, Ph.D., from UCLA's Centre for Human Nutrition reports which distribution of body fat is a more important predictor of heart attack risk than the conventional measurement of Body Mass Index (BMI), that is a measurement based on the ratio between the height plus weight.
Underwater Weighing - Underwater weighing, or hydrostatic weighing, is another way to determine the body fat . In this procedure, a person sits inside a specialized seat, expels the air from their lungs, and waist to height ratio is then submerged into a big steel tank of water to remain motionless whilst their underwater weight is recorded. This is repeated till a dependable fat is calculated. The purpose is to measure density of the body plus calculate yourfat weight. Because lean tissue is denser than fat tissue, this way may determine the buoyancy of a individual while underwater. When considered the gold standard offat measuring, the equipment is quite costly, creating other methods more attractive.
The perfect waist size will be between 45%-47% of the height. In other words, if you're 70 inches tall you're perfect waist is between 31.5 - 33 inches.
It is significant to be aware of your body in order to have a healthy body image, however, not too aware. Having certain fat on a body is not a bad thing, only the lack of fat or the excessive presence of fat is what can be dangerous to the health. Use the wellness resources available online as a reference to see if you're keeping the body healthy.