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| Fact |
Sport |
In
order to perform at your peak, you need to keep your body
hydrated. If you lose too much fluid and become dehydrated,
you can become tired, your heart can be stressed, and you
can even suffer from heat stroke. The best way to stay hydrated
is to drink a lot of fluids before, during, and after exercise.
When you exercise you sweat and sweat is made out of a combination
of water and electrolytes which contain salts such as sodium,
chloride, and potassium (that is why skin tastes salty after
sweat dries). Drinking water will replace the water lost
when you sweat but what about those salts? In order to replace
those, you need to ingest electrolytes and sports drinks are
a great source. [top]
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Having
trouble getting the bow to shoot off the arrow and hit the
target? The trick is to make sure that you are giving the
arrow as much energy as possible. As you pull back on the
bow’s string, you are allowing it to store up elastic energy.
As the string straightens back out, it transfers all of that
energy to the arrow. The more energy you give the string,
the more energy the arrow will have. The more energy the
arrow has, the higher its velocity will be and the easier
it is to aim. With all of this energy and velocity, it will
also be less likely to be affected by wind or other elements.
So, pull back with as much energy as you can and…bulls eye!
[top]
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See Also: Great Outdoor Games
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When
baseball players talk about the sweet spot they aren’t referring
to the ice cream stand. They are talking about a special
part of the baseball bat. They know they will get the best
results if they hit the ball with the sweet spot because all
of the energy will go into pushing the ball forward, none
of it will go back into the bat itself. The scientific term
for the sweet spot is the “center of percussion” and it is
easy to find. When you hit a ball with the sweet spot of
the bat, you will feel very little vibration in your hands.
All you have to do then is hold a bat and bounce a ball up
and down the length of it. When you bounce the ball near
the top, you will feel a force pushing against your fingers.
When you bounce it too close to the base of the bat, you will
feel vibrations in the palm of your hand. Somewhere in the
middle is the sweet spot where you won’t feel any pressure
on your hand. Be sure to hit the ball with the sweet spot
and see how far it flies!
[top]
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It
is obvious that weather conditions like heavy wind, rain,
or snow can affect a baseball game, but what about atmospheric
density? Atmospheric density is a scientific term used to
describe how many air molecules there are floating around.
When you are in a ballpark up in the mountains, you are at
altitude and the air is thinner. That means that there are
fewer air molecules to get in the way of the ball. In those
conditions, hits that might be routine fly balls can sail
over the fence for a home run, and hitters who might not try
for home runs can suddenly think about swinging for the fences.
Humidity also plays a role in atmospheric density. When it
is humid out, water molecules mix with air molecules and the
air is said to be heavy. Under those conditions, the air
and water molecules will slow the ball down so you need to
hit even harder.
[top]
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Basketball
players don’t spin the ball when they shoot to cause the ball's
path to curve, like in baseball. Basketballs move too slowly
for that to happen. So what's the purpose of backspin and
more importantly, how can it help your game? Backspin on
the ball is used to help it to bounce into the net after it
hits the rim or backboard. The spinning ball, after making
contact with the rim or backboard will bounce back in the
opposite direction. Since the net is right there, it is very
likely that the ball will drop in. In order to achieve backspin,
pull the top of the basketball slightly toward you as you
shoot it and watch your points add up. [top]
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If
you want your kayak or canoe to make a big turn, you need
to think about where the oar is hitting the water. When an
oar goes into the water, it exerts a force called “torque”
which causes the boat to turn in that direction. The formula
scientists use to figure out the amount of torque depends
on the distance between the center of the boat and where the
oar goes into the water. If the distance is short (if the
oar goes in right next to the boat), the torque is less and
the boat won’t turn very much. If the distance is longer
(if the oar is held out away from the boat), the torque is
greater and the boat will make a big turn. Try experimenting
with this formula the next time you are in a canoe or a kayak
to see how big you can make your turns. [top]
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Do
you have trouble getting up any speed when you go cross-country
skiing? Are you too busy slipping and sliding to really get
moving? Don’t worry, the problem probably isn’t your technique
– you are just missing the secret skiing ingredient – wax.
When you go cross-country skiing, you need to have the ski
grip the snow just a bit in order to be able to push off for
the next glide. Without wax, skis just slip on the snow.
The wax sticks to the snow just enough to hold it in place
so that you can get a good push. Try waxing the bottom of
your skis next time and see if it makes a difference. [top]
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If
you are learning how to ride a bike, take a lesson from science
– it is easier to stay balanced on the bike if it is going
fast than if it is standing still. It seems like it should
be harder to ride fast but it is actually easier, because
of angular momentum. This scientific force makes wheels want
to keep turning in the same direction and position as they
have been. So as your bike wheels spin underneath you, they're
actually helping you stay upright as their angular momentum
resists changes in the bike's upright position. The greater
the momentum, the more they’ll fight to stay balanced .
[top]
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If
you’ve ever ridden a regular street bicycle down a rocky hillside,
you’ve probably learned that it didn’t do much to keep you
from feeling every little bump. That is because regular bicycles
don’t have the suspension systems that mountain bikes have.
Suspension systems allow the wheels of the bicycle to move
up and down to absorb the shock while keeping the frame, and
the rider, moving smoothly. These systems have two essential
elements – the spring and the damper. The spring is what
allows the wheels to bounce up and down with each bump and
the damper is what stops them after just one bounce. If you
plan to do serious mountain biking, invest in a bike with
a really good suspension system to help protect your body
from those painful bumps! [top]
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Bicycle
helmets aren’t just for safety, they can actually help you
ride faster! Studies have shown that helmets can decrease
the aerodynamic drag that a bicyclist encounters by approximately
2% over a rider with no helmet. Because of the smooth surface
and the shape of the helmet, air flows over the rider’s head
more easily, allowing the rider to cut through the air with
less friction. Therefore, the right helmet not only protects
your head, but can also give you a competitive edge in a bicycle
race. [top]
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How
do Olympic level divers go into the water with such a little
splash? Diving coaches have studied the physics of water
and they understand how waves and splashes are created. They
know that if an object goes in a vertical, straight up and
down position, it will go smoothly into the water (think about
a diver ripping straight into the water). This happens because
the surface area of the object that collides with the water
is very small. Compare this entry to one created by a belly
flop or canon ball. Those jumps create a big splash because
there is a much bigger surface area hitting the water. So,
if you want to learn to dive without making a splash, try
keeping your body vertical. [top]
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Did
you know that the temperature of the ice in an ice rink can
affect your skating? It’s true! If the ice is 26-28 F, it
is softer, will grip the blades better, and is less likely
to shatter under the force of a jump (which is why figure
skaters prefer it at this temperature). If the ice is colder,
say between 24-26 F, it easier for skaters to make quick turns
and it is less likely to get chewed up (which is why hockey
rinks are kept at this temperature). So, the next time you
strap on skates, pay attention to the ice. If it is warmer
and softer, try jumping and spinning, if it is colder and
harder, try a slap shot.
[top]
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Ice
is slippery so if you step on it with skates you will glide
a little. That slippery surface won’t help you go very fast
though. For that you need some friction which can be created
when the blade pushes into the ice. Most beginners try to
get moving by putting one foot in front of the other, like
walking, but they never get very far because they never generate
any friction. Instead, try pushing the middle of your skate
blade to the back diagonal 45 degree angle. By repeating
this step, you will have enough friction to get around the
rink in no time.
[top]
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Want
to learn to spin like Michelle Kwan? Better think about your
arms. That’s right, your arms, not your feet, determine how
speedy your spins will be. Spinning objects have angular
momentum which is a property that describes the mass, radius,
and speed of a spinning object. Since your mass stays the
same whether you are spinning or standing still, the other
two components take over to balance each other out. If the
radius gets bigger, the rate of speed gets smaller and vice
versa. So, if you stretch out your arms, you are increasing
your body’s radius which will decrease your speed. If you
pull your arms in tight to your chest however, you will decrease
your radius and increase your speed. [top]
See
Also: Michelle Kwan Biography
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Whether
you are a beginner ice skater or you are working on that triple
axel, you need to pay attention to your blades. Understanding
the science used in the blade will help you be a better skater.
Blades on both hockey and figure skates are concave which
is a scientific term that means that there is a hollow area
carved into the blade, running down the center, from front
to back. As a result of this hollow, blades have two edges
– the inside edge which is toward the big toe, and the outside
edge which is toward the pinky toe. Being able to switch
from an edge (when you lean to one side) to the flat of your
skate (when you skate with the whole blade touching the ice)
allows you to control friction. When you dig the edges into
the ice, you create friction which slows you down – very handy
when you need to make a quick stop or change direction. When
you switch to a flat there is less friction, making it easier
to glide in a straight line.
[top]
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You
know that an NFL player can throw a football farther than
you can, but do you really know why? First, let’s examine
the properties of a football itself. Footballs are different
from balls used in other sports because they only spin around
the axis that runs lengthwise from one end of the ball to
the other. The key to throwing a football well is to make
it spiral around that axis. The faster is rotates as it zips
through the air, the less it will wobble. Wobbly balls don’t
go very far but steady ones can go all the way for a touchdown.
[top]
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Want
a hint on how to throw a Frisbee really far? Try to launch
it so that the front edge is pointed slightly down to the
ground. Any flat object moving this way will deflect air
toward the ground. When the air is forced down, an equal
and opposite force pushes up on the Frisbee, keeping it flying
high. If you throw it with the front edge pointing to the
sky, the air won’t be able to help and the Frisbee won’t go
very far. [top]
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Trying
to putt a golf ball into a hole can be a frustrating experience.
More often than not, the ball overshoots the hole or stops
just before going in. Fortunately science can help. With
a few calculations, you can figure out just how much force
you need to apply to the ball to make it go in. The first
thing you have to look at is the putting green’s surface.
Is it bumpy? How much grass is there between the ball and
the hole? Each bump and blade of grass that has a force applied
upon it by the ball reacts with an equal and opposite force
back on the ball. This force is called friction and it slows
down the velocity of the ball. So, for every obstacle, you
need to add just a bit more force to your swing. Another
thing to consider is whether you are putting uphill or downhill.
If the hole is uphill, you will have to apply a larger force
to the ball to make up for gravity’s pull. If the hole is
downhill, you will apply a smaller force because gravity will
do some of the work for you. [top]
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If
you fall when you try to do a handstand, you aren’t alone.
Handstands are very difficult because if they aren’t done
properly, gravity will pull them right over. One trick is
to keep your body as straight up and down as possible. If
your legs bend, for example, gravity will grab on and pull
them toward the ground, causing you to fall. Another trick
is to keep your body as still as possible. If your legs or
torso start to swing, they will create momentum which will
also cause you to topple over. [top]
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The
most important part of a successful slap shot happens before
the stick ever hits the puck. If a player just whacked at
the puck, it wouldn’t go very far. The stick needs to be
loaded first. A player can load the stick by raising it up
in the air and applying pressure by pushing the lower hand
against the shaft and holding the upper end of the stick close
to the body. This technique causes the stick to bend a little
which loads it with potential energy. When the stick comes
contact with the puck, it hits it with all of the player’s
strength plus all of the loaded energy. Score! [top]
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If
you think a horse doesn’t follow the laws of physics, you
are wrong. Horses understand both pressure and torque. When
you are riding a horse, you hold onto the reins. The reins
help you communicate with the horse by letting it know where
you want to go. By pulling on the reins you are putting pressure
on them, that pressure is transferred into the bit in the
horses mouth and the horse knows you are trying to tell it
something and it will respond to your commands. Reins exert
a force called “torque” which causes the horse to turn in
the direction that you are pulling. The formula scientists
use to figure out the amount of torque depends on the distance
between the center of the horse and how far out to the side
your hand is when you pull. If the distance is short (right
behind the horses head), the torque is less and the horse
won’t turn very much. If the distance is longer (way out
to the side), the torque is greater and the horse will make
a big turn. Try experimenting with this formula the next
time you are horseback riding to see how big you can make
your turns. [top]
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Ski
jumpers might look like they are just effortlessly flying
off of a ski jump but there is a lot of physics involved.
If you ever want to try ski jumping, pay attention to how
science can help. As jumpers come down the ramp, they try
to build up as much speed as possible while maintaining control.
To minimize air resistance, they get in a low crouch, point
their arms forward, and bend their heads slightly downward
like a diver entering the water. Halfway down the ramp,
they begin to re-position their bodies in preparation for
leaping off. Near the end, where the ramp begins to curve
upward, they raise their hips slightly while pressing the
chest tightly against the knees. This makes their legs act
like a coiled spring storing additional energy for the takeoff.
About three meters (10 feet) from the end of the ramp, jumpers
begin their final adjustments before takeoff, bringing their
arms perpendicular to the ground and rising up slightly.
The most important part of the jump occurs at takeoff. Within
a tenth of a second, jumpers must combine two motions at once,
leaping both forward and upward. The timing of the takeoff
leap is what makes or breaks a jump. If jumpers spring before
they reach the exact end of the takeoff table, their skis
will point down, causing extra wind resistance which results
in a short jump. If they spring too late, their skis are pointed
too high, resulting in a serious loss of control. In the
air, jumpers become flying projectiles, using their bodies
and skis like a giant airfoil. They lean forward, producing
a positive angle of attack on the wind. They hold their skis
in a large V with the open end pointed forward. This positioning
increases the surface area below the body, providing more
lift toward the end of the flight. It extends the time in
the air and the distance of the jump. [top]
See
Also: Winter X Games
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The
next time you go sledding down a hill, try an experiment.
On the first run, sit up in your sled. On the second run,
lie flat. Which run was faster? Due to the laws of aerodynamics,
the second run will be faster. As air rushes past the sled,
it collides with both the sled and with your body, causing
friction which slows everything down. When you sit up, your
body will bump into more air molecules, causing you to slow
down a great deal. By lying down, you reduce the amount of
molecules your body hits which helps you move faster. [top]
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Clearly
gravity is what keeps snowboarders from flying off those mountains
and into space but how does the center of gravity affect performance?
Center of gravity is a scientific terms which is defined as
the balance point of any object – where the mass and weight
are equal on either side. For a snowboarder the center of
gravity is somewhere around the rider’s hips. The trick to
a successful trip down a mountain is to keep the center of
gravity, in this case the rider’s hips, over the edge of the
board that is digging into the snow. Any time an object’s
center of gravity moves beyond the base that keeps it up,
the object will fall. Ouch! [top]
See
Also: Winter X Game
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Want
a hint on how to kick a ball as far as you can? Think angles.
When you kick a ball, it actually moves in two directions
– vertical (straight up in the air) and horizontal (straight
out in front of you). When both the vertical and horizontal
forces work together, they cause the ball to fly in an arched
path. The shape of that path will determine how far the ball
goes. If you kick the ball in a sharp angle upward, it will
have a lot of vertical force but not very much horizontal.
So, it will go up very high but it won’t go very far down
the field. If you kick it at a lower angle, it won’t go very
high up in the air but it will travel much farther. [top]
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Soccer/football/
kickball
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How
do you know how hard to kick a soccer ball? Just ask Isaac
Newton, his second law will tell you all you need to know.
It says that force equals mass times acceleration. That means
that an object’s speed depends on how much force you apply
to it. The more force you apply, the faster the ball will
fly. If you want to kick a ball harder to make a goal than
you would when passing it to another player, think about the
amount of force you need to apply to accomplish your goal.
[top]
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If
you have tried to race around the ice but feel like something
is holding you back, take a look at what you are wearing.
Your clothing will affect your speed. Take a look at competitive
speed skaters, they all wear space age looking bodysuits.
They know that when they skate, they collide with air molecules.
The molecules want to grab hold of them and slow them down.
By wearing smooth bodysuits, the skaters are able to escape
those pesky molecules. The air flows over the smooth surface
without slowing anyone down. Try wearing clothing that fits
tightly to your body and is made of smooth fabric such as
Lycra or Nylon. I’ll bet your speed improves!
[top]
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In
order to ride the waves, you need to understand how they work.
Ocean waves, like all other waves, are defined as traveling
disturbances that carries energy from place to place. The
energy that is being carried by ocean waves originates in
wind or the gravitational forces caused by the sun and the
moon. Ocean waves consist of many water molecules traveling
in clockwise circular orbits. When the waves are far off
shore in deep water, the water molecules are able to travel
undisturbed in their circular orbits. As they approach the
shore, the water becomes shallow and the bottom of the orbit
comes in contact with the ocean floor. The surfer wants to
catch the wave just as it is crashing. At this point, the
wave has maximum momentum. In order to catch the wave your
momentum must be equal to its momentum. You accomplish this
by facing your body in the same direction as the wave's motion.
Use your arms to paddle until your momentum is equal to the
waves. At the instance that this occurs, you will suddenly
feels the board being carried along by the wave. You can then
stand up and surf. Cowabunga!
[top]
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When
you swim, the last thing on your mind is probably the placement
of your hands. Think again because your hand movements can
make a big difference! The old swimming style was to pull
your hands straight through the water in a straight line under
the body, like canoe paddles. Instead, today’s top swimmers
pull their hands through the water in an S shaped pattern,
like a motorboat propeller. This newer method creates less
friction with the water and helps the swimmers go faster.
Try it to transform yourself from a canoe to a motorboat!
[top]
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If
you are a competitive swimmer, fashion and hair are very important.
In a race, your goal is to fly through the water as quickly
as possible. The problem is that water molecules want to
grab onto you, causing drag which will slow you down. In
order to reduce drag, you can do two things. The first is
to shave. The hairs you have on your arms and legs are perfect
handles for those pesky water molecules. Without them, the
water will flow more smoothly over your skin. The second
thing to consider is your bathing suit. Swimmers have been
using technology to come up with extremely thin, smooth bathing
suits made of Nylon and Lycra. With nothing in the fabric
for the water to hold onto, it won’t slow you down.
[top]
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Did
you know that the strings on your tennis racket have a lot
to do with your game? Rackets with loosely strung strings
give the ball lots of power. Since the strings are loose,
they bend a little when the ball hits them, storing elastic
energy. As the strings flatten out again, they return that
energy to the ball, giving it extra oomph. It can be hard
to control all of that energy though, which is why some players
like to string their rackets more tightly. They won’t get
as much power behind the ball but they will be able to control
it a little more. If you want to improve your game, check
out the tension in your racket strings and adjust it as needed.
[top]
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If
you put science to work for you on the tennis court, you’ll
be an ace. When they are hit, tennis balls fly through the
air with a certain velocity. Since the ball is one solid
piece, it all travels at the same velocity. When you hit
it with spin though, you affect the ball’s velocity. Let’s
say you use topspin, for example. If a ball is hit with topspin,
by striking down from the top, the velocity of the top of
the ball will be greater than on the bottom so the top will
hit the ground at a faster rate than the bottom. That difference
will create a new angle for the bounce which can confuse the
other players since they won’t be expecting it to bounce in
that way. You can also use backspin by hitting up from the
bottom and sidespin by striking the ball on its side. No
matter which spin you use, it is sure to make your opponents
dizzy!
[top]
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If
you feel pain after running, you need to pay more attention
to Newton’s third law. This law says that when one object
exerts a force on a second object the second object always
exerts a force equal to, but in the opposite direction of
the original force. When you run, your foot strikes the ground
with the full force of the your mass and acceleration but
the ground also exerts that same force on your foot. That
is why manufacturers of running shoes are constantly developing
new technologies to cushion the foot. Cushioning is used
to decrease the amount of force felt by the runner's feet
and joints. This works by increasing the amount of time it
takes for the force to reach the runner's feet. The more cushioning
provided in the shoe, the more time it will take for the runner
to feel the force caused by striking the ground. The increased
amount of time and the decreased amount of force helps to
minimize the wear and tear on the runner's body. Make sure
your running shoes have lots of cushioning and you’ll feel
much better.
[top]
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Do
you sometimes slip when you run on a track? Maybe you don’t
have the right shoes. Competitive runners use shoes with
small spikes on the soles. Why are there spikes on the bottom
of running shoes? In a sport that is all about speed, wouldn’t
spiked shoes slow the runner down? You got it – these runners
use the spikes to slow them down so they can speed up! Racing
tracks can be slippery. If a runner slips, time is lost and
the runner can even get injured. The spikes create just enough
friction between the shoe and the track to stop the runner
from slipping. With sure footing, they are free to speed
away. [top]
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If
you are having trouble acing your volleyball serve, get off
the ground. When serving, you want to hit the ball as hard
as possible with the least arc, while still clearing the net.
In order to get it over the net but still have it land in
the court, you need to hit it at an angle. If you stand while
serving you have to be very precise and hit the ball at just
the right upward angle. If you jump up while you serve you
don’t have to hit it at such a sharp angle. If you jump up
high enough, you can even hit the ball straight ahead or downward
and it will still go over the net. Those shot are easier
so think about the angles next time you serve.
[top]
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