Thomas Calculus 12th Edition Textbook and helping material
Sport science
1. Sport refers to the exercise of skill in a physical activity which is often competitve,
and carried on for its intrinsic enjoyment, including that of its spectators. Sport is generally
recognised as activities based in physical athleticism or physical dexterity. Sports are usually
governed by rules to ensure fair competition and consistent adjudication of the
winner.Records of performance are often kept and reported in sport news. Sport is a major
source of entertainment with spectator sports drawing large crowds and reaching wider
audiences through sports broadcasting. Sports are an incredibly important contributor to
human nature in our pussified society. The lack of responsibility and risk taking swells to the
point where people avoid any kind of competitive activity because of the inherent risk of
failure. Participating in sport at any level will replace the necessary competitive edge in an
individual and kindle the fire of dedication, hard work, and almost reckless intensity.
A little-considered aspect of sports is the relationship it has with physics. The reality,
though, is that sports and physics are intimately connected. This is because every sport
depends on an athlete's ability to exert force. Whether it's taking off from a starting block in a
sprint, delivering a knockout punch or hitting a baseball with a bat, an athlete uses force.
Force is one of the key points in the study of physics, so this relationship is symbiotic.
An object's momentum is a product of its mass and velocity. The faster or bigger it
is, the more momentum it can deliver; a balled-up piece of paper needs to move much faster
than a baseball in order to generate the same amount of momentum. The relationship between
sports and momentum is that momentum never goes anywhere. Rather, it is just transferred.
So, when you kick a soccer ball, you are transferring momentum to that soccer ball. The
faster you can move your foot or the heavier your foot is (or both), the further the ball will go
because you generated more momentum.
Aerodynamics is a physics term that describes an object's ability to overcome air
resistance. A football, for example, overcomes more air resistance than a baseball when
thrown correctly because of its unique shape -- the football "cuts" through the air rather than
smashing into it. Aerodynamics' relationship with speed means it has a relationship with
almost every sport. Running with proper form, for example, allows you to overcome
aerodynamics by situating your body correctly. This will allow you to run faster than
someone at an equal or greater fitness level but without proper running form.
2. Force is similar to momentum, but it is a product of mass and acceleration rather than
being a product of mass and velocity. So, a football player who weighs 300 pounds and is
capable of producing a large amount of acceleration will be able to produce more force than a
football player who weighs the same amount but cannot accelerate as quickly. This illustrates
the relationship between muscle and fat. If someone weighs 300 pounds, 90 pounds of which
are fat, then he will not be able to produce as much force as someone who weighs 220
pounds, 5 pounds of which are fat. This is because acceleration comes from muscle, not fat;
the fat is only providing half of the equation.
Every single body and thus the athletes themselves, is made up of individual
components each of which has its own weight. So our weight is just the sum of individual
weights, of components such as our arms, legs, etc. The point, about which the distribution of
these individual weights is symmetrical, is the center of gravity of the body. Thus, if a body
has more mass distributed in its upper part, the center of gravity will be closer to the top of
the body. This applies to humans, as the center of gravity of an average person is located
approximately at a height of one meter, thus being above the waist. There are two properties
of the center of gravity that have a great impact on sport. First of all its location is dependent
on the shape of the body.
So if the same body is to take a different shape, the position of the center of gravity
will shift. An athlete that bends his/her legs will lower his/her center of gravity position. This,
amongst other things, will result in greater stability, something especially important in sports
such as wrestling. Also, and this may sound the strangest, the center of gravity can lie entirely
outside the body itself. For example, if the body is hollow it will literally be positioned
somewhere in the air. During the Olympic Games in Mexico, in 1968, an, until then unknown
athlete, the American Dick Fosbury, came from nowhere to teach the world about both of
these properties.
The truly ingenious leap in the technique was that by clearing the bar with his back
and by changing the shape of his body, the athlete could clear the bar without his center of
gravity having to also clear it. By this change in body shape he was able to move his center of
gravity outside his body. The energy required for a jump depends on the maximum height of
the center of gravity and so by lowering its position one also lowers the energy required to
clear the bar.
3. A key physical principle is the fact that an object will not stop moving until
something stops it. Friction plays a key role in stopping objects because it creates constant
resistance on objects such as balls rolling along a field, people running down fields and ice
skates against ice. In every sport, friction represents a stopping force that needs to be
overcome; the better you can overcome this force, the better your chances are at success in
your sport.
The Physics Of Soccer — The Magnus Effect. When a soccer player kicks a ball
off-center it causes the ball to spin. The direction and speed of the spin will determine how
much the ball curves during flight. It's the same principle as a curve ball in baseball. When
throwing the ball, the pitcher imparts a fast spin which causes the ball to curve during flight.
As the ball spins, friction between the ball and air causes the air to react to the direction of
spin of the ball.
As the ball undergoes top-spin (shown as clockwise rotation in the figure), it causes
the velocity of the air around the top half of the ball to become less than the air velocity
around the bottom half of the ball. This is because the tangential velocity of the ball in the top
half acts in the opposite direction to the airflow, and the tangential velocity of the ball in the
bottom half acts in the same direction as the airflow. In the figure shown, the airflow is in the
leftward direction, relative to the ball.
Since the (resultant) air speed around the top half of the ball is less than the air speed
around the bottom half of the ball, the pressure is greater on the top of the ball. This causes a
net downward force (F) to act on the ball. This is due to Bernoulli's principle which states
that when air velocity decreases, air pressure increases (and vice-versa).
4. Therefore, when a soccer player kicks the ball right of center the ball spins counter-
clockwise and the force acts left, causing the ball to curve left. When the ball is kicked left of
center the ball spins clockwise and the force acts right, causing the ball to curve right. This
can result in a ball deviating as much as several feet from the original trajectory by the time it
reaches the net. This is no doubt a useful strategy when attempting to make a goal, since it
makes the path of the ball less predictable to the goalie as he's preparing to block the shot.
Physics Of Basketball — Hang Time .Jumping is a major component of the physics
of basketball. When a basketball player jumps in the air to make a shot he can appear to be
suspended in mid-air during the high point of the jump. This is a consequence of projectile
motion. When an object is thrown in the air it will spend a large percentage of time in the top
part of the throw.
A basketball player can jump as much as 4 feet in the air (vertically). And the higher
he jumps the greater the hang time (the total time he is airborne), and the greater the time he
will appear suspended in mid-air during the high point of the jump.
Typically, there is a horizontal and vertical component in the jump velocity at take-
off. The magnitude of the vertical component of the velocity at take-off will determine the
time the player spends airborne (since gravity acts in the vertical direction and will act on the
player to bring him back down). Thus, the vertical component of velocity, after take-off, will
change with time.
The horizontal component of velocity remains constant throughout the jump since it is
not affected by gravity.You can visually see that almost half the hang time is spent near the
top of the arc. Using some mathematics one can calculate the time spent in the top part of the
jump.The interesting result tells us that half the hang time is spent in the bottom 75% of the
jump. The remaining time is spent in the top of the jump (the top 25% of the jump). In other
words, half the jump time is spent in the highest 25% of the jump (the top part of the arc).
This explains why a basketball player appears to "hang" during the jump. So, a player who
can jump 4 feet vertically will have a hang time of around a second, with half a second spent
in the high part of the jump.
5. The next application of physics is in swimming.Swimming races are often decided by
tenths or hundredths of a second. With a margin like that, the tiniest details that affect a
swimmer's speed can make the difference between winning and losing. Swimmers must do
everything they can to reduce the water resistance against their body as they propel forward.
Resistance will increase with the surface area exposed to the water, so the more
streamlined a swimmer can make her body, the quicker she will go. The smoother this
surface is, the better, as well. That's why swimmers often shave all their body hair, wear
swim caps to cover their heads, and cover much of their bodies with specially designed
swimsuits that mimic shark's skin or other surfaces for greater hydrodynamics.Swimmers
must also think about buoyancy, the force that keeps them afloat. Because water is more
resistant to movement than air, it is in athletes' best interests to swim as close to the surface as
possible so that more of their bodies are exposed to the less resistant air than to the dragging
water.
The principle of angular momentum is immediately apparent when watching Olympic
gymnasts spin and twirl, aiming to win higher scores by packing in more rotations.
All objects spinning around a point have a quantity called angular momentum that
depends on the object's mass, speed and how spread out it is around its center of gravity.
Unless some outside force interferes with the system, its angular momentum will be
conserved. Thus, a gymnast can spin faster by pulling in his arms and legs as tightly as
possible, thus reducing the space over which his mass is spread out. In response, the
gymnast's speed will increase to make up the difference and keep his total angular
momentum constant.
Newton's third law of motion also plays a great role in gymnastics. The law states that
for every action, there is an equal and opposite reaction. Gymnasts take advantage of this by
pushing hard against the floor, the balance beam or the vault, so that these surfaces push back
hard against them, giving them lift into the air.
Olympic divers aim to do gorgeous twists and turns in the air, and then glide as
seamlessly into the water as possible. The bigger the splash made going in, the larger the
deduction taken from a diver's score.
6. Divers also take advantage of Newton's third law. By jumping down on the diving
board as hard as possible, divers can cause the board to push back up on them, giving them a
larger vertical velocity to spring high into the air. The more time in the air, the more time a
diver has to complete her somersaults.
As divers near the water, they try to line their bodies up as vertically as possible, with
arms and legs streamlined into a thin pole.
"The reason why they want to enter the water vertically is that they're going to go into
the water and bring all of that water down with them," explained University of Southern
California Dornsife professor of biological sciences and biomedical engineering Jill McNitt-
Gray in a video on the physics of diving. "Once you're under the water, you want to create a
small hole, so the water that comes up doesn't make a big splash.
Action and reaction play a significant role in archery as well. To shoot an arrow
straight and true at a target, archers must first impart a forward force on it. To do this, an
archer will pull back on the bow string, thus storing potential energy in the string. When the
string is released, it imparts this potential energy to the arrow in the form of kinetic energy,
propelling the arrow forward.
To keep an arrow on its intended target once it is released, its shaft is tipped at its end
with fletching in the form of bird feathers or a plastic substitute — traditionally, three per
arrow. Fletching offers aerodynamic stability through air resistance. If some force, such as air
turbulence, tries to push the arrow off its straight course, the fletching produces a drag against
that change in motion, hindering the movement off course. Sometimes fletching can induce a
spin on the arrow, which can further improve its stability and accuracy by equalizing forces
from air turbulence.
7. Badminton is a racquet sport where players pass a projectile called a shuttlecock or
birdie back and forth over a net. In contrast to spherical balls, shuttlecocks, which are balls
with cones of feathers or nylon protruding from their sides, travel much differently through
the air. Their feathers provoke a much larger drag force from air resistance, so they lose
speed much more quickly than balls do.
Like fletching on an arrow, the feathers on a badminton shuttlecock improve its
aerodynamic stability — so much so that regardless of which direction the feathered cone is
facing when the shuttlecock is struck, it will quickly orient itself so that the feathers are
pointing backward as it flies through the air. Players must consider the unique aerodynamics
of their sport when aiming the shuttlecock, and must exert more force than would be needed
on a comparable ball to hit the shuttlecock full across the court, because of its high drag.
In the nutshell,application of physics in sports are very important in order to improve
human's achievement.Before,scientist approved that human cannot runs below than 10
seconds but now Usain Bolt has proved that we can do it.So,from day to day we discovered
more about sports and make it better to mankind.
REFFERENCES:
www.topendsports.com
www.real-world-physics-problems.com
www.angelfire.com
www.livescience.com
neutrino.phys.washington.edu
8. THE APPLICATION OF PHYSICS IN SPORT
NAME:NUR HANIS SOLEHAH BINTI MOHD ROSLI
ID:19151
IC:950504-02-5340
LECTURER:MR. BADRUL IHSAN
CODE:KFP 1021