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How is friction used in basketball
How is friction used in basketball
The physics of basketball and bracketology
The March Madness craze begins soon. People have already started creating brackets to figure out who will be the best team in college basketball. With all this basketball on people’s minds, it’s a good time to look at some of the physics, math, and art behind the most exciting sport in March.
The Ball
The first and most important element of the entire sport is the basketball. The ball hasn’t always been the bumpy ball we use today. When teams first started playing, things like soccer balls were used. If you picture a soccer ball, you realize it’s far smoother than a basketball.
Players had trouble dribbling or passing the ball because it would slip out of their hands. So the ball was made bigger, and bumps were added to make the ball easier to hold on to. The bumps cause more friction between the ball and the player’s hands, and the friction makes the ball easier to handle. With bumps added to the basketball, actions such as dribbling and passing are easier.![]()
Both of these actions have elements of physics.
The Dribble
The simple act of dribbling the ball highlights each of Newton’s three laws. When you start to dribble:
- You and gravity both apply force on the ball.
- The ball accelerates toward the ground with the force of gravity.
- After the ball hits the ground, an equal but opposite amount of force acts on the ball, forcing it back up into your hand.
The more force applied to the ball at the beginning of the dribble, the higher the bounce. The height of the bounce is also affected by the surface being dribbled on and the air inside the ball. If the surface is denser, less force is transferred away from the ball, and the ball bounces higher. The most common basketball surface in a gym is maple wood because it has a high density rating and high shock resistance, which helps with bouncing and athlete safety when jumping. The ball has far less bounce on a soft surface such as carpet.
The air inside the ball helps with the transfer of energy.
When the ball hits the ground, the air inside is compressed. The energy in the compressed air pushes back in the opposite direction of the force and causes the ball to bounce. This is why a ball with less air won’t bounce as well.
The Pass
When passing the ball, players must always compensate for gravity. You normally aim to pass the ball to someone at chest level. If you try to pass a ball straight to someone’s chest, you will probably hit them lower than intended. This is because gravity is constantly forcing the ball toward the ground. To compensate for gravity, the trajectory of a pass is usually above the intended target.
The Shot
The same compensation for gravity is present when you shoot the ball. With the basket positioned 10 feet off the ground, a straight shot won’t ever make it into the hoop. When shooting a basket, you apply an upward force to the ball and gravity brings the ball back down. The initial force you apply to the ball along with the force of gravity is what gives your basketball shot that pretty arc similar to a parabola.
Every shot in basketball is a little taste of geometry, and the best shot that applies a little bit of geometry ends with an always-satisfying swish.
The Bracket
So, we can’t talk spring ball without including the infamous March tournament bracket.
Some might say picking the right outcomes in the bracket is an art. Others might contend it’s a science and that you can apply engineering and statistics to selecting your top teams. One example is the University of Illinois’ analytics-based approach.
With a little creativity, you could even use basketball to test some physics lessons in class. A simple activity could be to vary air pressure in a basketball and test its effect on the bounce of the ball.
Or check out these ideas:
- “How to Incorporate March Madness into Your Classroom”
- “March Madness: Using Tournament Brackets to Debate Academic Questions”
- "Basketball Science: Hooking March Madness Fever to Hands-on Sports Science Experiments”
With a little imagination, you could easily turn the hype around basketball during March into an exciting hands-on STEM education experience for students!
TOPICS: IN THE CLASSROOM, IDEAS & INSPIRATION, Science, STEM, Engineering
What's the Purpose of the Dots on a Basketball?
To reveal just why and how those little speckles made their way to your basketball, we’ll need to take a trip back to the early days of the sport, dabble in a little bit of physics, and swing on over to the leather company which makes those dots possible.
Physics and the Early Anatomy of a Basketball
Ever tried to grab a handful of ice cubes, only to have them all slip out of your hands?
This is a consequence of an absence of friction. When two forces smash together, friction is the force that breaks up, slows down, or otherwise alters that movement. The more points of contact an object has with a surface, the more friction it has. It’s what makes concrete pebbles easy to run on and those traction marks on your snow boots work against the ice to keep you from flip-flopping on your bum.
Without much friction, things get slippery. In the ice cube example, those slippery cubes, with their sleek, non-resistant surfaces, combined with your undoubtedly well-moisturized hands, have few points of contact upon which to create friction. In line with Newton’s First Law of Motion, the ice cubes then freely exercise their right to be objects in motion that stay in motion and, thus, slip out of your hands and scatter all across your kitchen floor.
Such a diminished level of friction is beneficial in some sports. It’s what makes bowling balls glide down the lane and adds fluidity to Sasha Cohen’s figure skating routines. But for basketballs? Friction-less balls would scatter about like so many large, bounce-able marbles.
And that’s exactly what the early basketballs were doing all across the court in 1894. At the time, teams were using soccer balls. The slick surface of the soccer ball, combined with the oil-polished hardwood gym floors, created a slip-and-slide during game time. Players became less concerned about the purpose of the game (making baskets) and more concerned about just trying to hold on to the ball.
Fortunately, James Naismith, the charming, well-mustachioed P.E. teacher who invented the game back in 1891, was not about to let a soccer ball get in the way of his legacy. Naismith called forth his good buddy and sporting goods maker, A.
G. Spalding, and the two collaborated on a design for a new ball that would enhance the players’ ability to handle it. They decided that the ball not only had to be larger, but it also needed an added source of friction.
This is where the dots come in.
The dots, combined with a rough, well-treated leather, would create more points of contact with the court and enhance the amount of friction over the ball. Thus, the first pebbled Spalding basketball was born, and the players celebrated: they could dribble the ball and it wouldn’t go flying out of their hands. It was a miracle of innovation, and one that sticks to this day.
The dots today
The dots (or “pebbles” as they’re known in the basketball-making trade) are all over basketballs today, and the Horween Leather Company has been manufacturing the NBA’s speckled leather for over 60 years.
Having started its foray into tanning back in 1905, Horween Leather nudged its way into the sports trade through its founders’ love of football.
One of the company’s founders, Arnold Horween Sr., had a strong history with the Harvard football team. Horween got him in touch with George Halas, the founder of the Chicago Bears, who then hooked Horween up with the Chicago-based Wilson football company. From then on, it was football-making destiny.
At the time of Wilson and Horween’s collaboration, Spalding was using an alternate leather tanning company to produce its basketball leather, but when that leather company fell to bankruptcy, Spalding found itself looking for a new source of horsehide. Noting Horween’s reputation for quality NFL products, Spalding made the leap over to Horween. It paid off: Horween stands strong as not only the maker of all NFL and NBA game balls, but also as the only tanning company surviving in all of Chicago.
Horween’s process of making that special NBA-certified leather is no easy bag of chips. It involves inspecting, baiting, pickling, tanning, re-tanning “in tack” (i.
e.: adding essential oils to make the leather stickier and easier to grip), drying, and grading all the horsehide leather. At the end of its long journey, the leather is taken to a special press, where dots are embossed to create each individual pebble. Both basketballs and footballs get the exact same pebbling embossment (with the exception of Wilson-brand products, which has its own special mold).
While the extra points of contact provided by those tack-covered pebbles do wonders for a modern basketball, those speckles can’t completely prevent the ball slipping from your hands. When you play basketball, you sweat, and when you sweat, things get slippery, which can cause your high-quality basketball to slip straight out of your hands.
No shame! Even Michael Jordan got sweaty palms. While nothing can 100% insure that you keep your mighty grip on the ball at all times, a little human intervention can better prepare your ball for game play.
If you have a fairly new ball, consider breaking it in by playing a few practice games ahead of time. The contact of the ball with a surface, like, say, concrete (a surface ripe with friction-friendly pebbles), creates a more rugged terrain on your ball. The more pebbled your leather, the better the traction. The better the traction, the easier the ball is to handle. The easier the ball is to handle, the more likely you are to win that game of HORSE with your neighbor (depending who your neighbor is).
Physics in basketball - online presentation
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Physics and sports
Completed by a student of the ME-11 group:
Flegant A. E.
Lecturer: Belushkina Yu. V.
Physics in basketball
Purpose of work:
to show how knowledge of physics
can be used in
basketball
Physics surrounds us everywhere
,
Whatever we do,
wherever we go.
Her laws accompany us.
And even in sports
they act.
Basketball is a sport of the strong and young
Today basketball -
is an athletic game,
which is characterized by high
motor
activity,
great intensity
game
actions,
requiring
from the
player
ultimate mobilization 90 capabilities and speed.
The game consists in playing one against
of one team of 5 and try to score more than
balls in the enemy basket.
In modern basketball, one can get high sports results
by combining a good game with the use of
physical laws.
During the game, the player must take into account the
physics of the throwing process:
• Dependence of the body movement range
on the flight angle;
• The effectiveness of the completed pass
is increased if the player is able to
assess the strength of his legs and arms,
applied to the ball to hit the ring or pass
to a partner;
• the use of the laws of conservation
of the energy and momentum of the ball hit at the moment of its receipt
has a great influence. This energy
is transmitted to the flying ball by the player's hands
.
Laws of physics in basketball
There are two sections in basketball technique: movement technique
(kinetic) and ball handling technique
(dynamic).
Kinetic
Structure
Dynamic
the structure
is connected with the movement
of the player in
space and
time: how he
moves -
quickly, but, along a straight line
or along a curve,
uniformly with
acceleration.
is related to throws
of the ball.
The dynamic
structure
is determined by the forces
created by the player
, which
act at the moment
of receiving a pass or
of throwing
Running
Running is the main means of movement
in the game.
While running on player
act
friction force,
gravity force,
air resistance force
.
Running speed can
increase due to
muscular efforts.
Jumps
To jump, the player creates with his muscles
such a "pushing force",
which allows him to jump,
get off the floor, overcoming the force
of gravity.
Throwing, passing
When throwing and passing the ball, the player
must evaluate the force
created by his legs and arms
and applied to the ball for
"losing" the ring or passing the ball
to a partner.
Catching the ball
At the moment when the ball is caught, a hit occurs,
transfer of energy and momentum.
The energy of the flying ball is transferred to the hands.
Kick
The essence of the game is to throw the ball into the ring.
99% of all balls that hit the upper corner of the "square"
, after bouncing off the backboard
will hit the ring;
and there is a regularity
: the angle of incidence
is equal to the angle of reflection (with
elastic impact).
RIGHT SNEAKERS
Quick acceleration from a standstill, rapid movements
of a basketball player in a game, maneuvers, turns, a sharp change
of directions, the need to stop immediately - all this
affects the outcome of the game.
Properly selected basketball shoes will dampen the force
of hitting the surface when jumping, create stability when
moving.
Basic requirements for
basketball shoes:
good grip on the
playground;
Jump Drum Softening
leg loads;
ensuring the freedom of movement of the athlete
.
12.
correct shoes CORRECT SNEAKERS
The outsole of the
basketball shoe provides grip on
surfaces and cushions vertical impacts
when jumping. It should be
wide and flat.
The quality of the sole for indoors and
for outdoors is different. Sole for smooth hall floors
- soft, corrugated,
anti-slip. Good
clings to wood flooring
rubber outsole. The
herringbone pattern further enhances
cornering and
stopping grip. Basketball shoes
for the street are equipped with a dense, hard sole
, resistant to abrasion on
asphalt.
I think many people paid attention to the fact that while running or walking
on the parquet, most of the
sneakers make a rather nasty sound (squeak).
It comes from the friction of the
coated sole. Even though this sound is
is unpleasant, it means that shoes like
are usually of high quality and allow the
athlete to brake in time and without problems
.
Conclusion:
The laws of physics are present in basketball, and their knowledge
helps to improve results in games. Thanks to this knowledge, the player
maintains health, develops
endurance and the will to achieve the goal.
Talent wins matches, team play
and intelligence win championships.
Thank you for your attention!
English Russian Rules
Basketball size: FIBA and US standards
Basketball is believed to have appeared on December 21, 1891. Then James Naismith, a physical education teacher from America, in order to interest students in sports, decided to hang two baskets in the hall and offered to play. The task is to throw the maximum number of points into the opponent's basket. There was no basketball back then. Used equipment for rugby and soccer. The first basketball appeared a couple of years later. It was not perfectly even, round and had a dark brown color. In addition, it flaunted lacing, which gave the players a lot of problems.
The first smooth inventory appeared only at 1935 year. After another 20 years, the color has changed. Television workers noted that the dark brown ball was hard to see on the screen. It was decided to change the color to yellow. Interestingly, for more than 50 years there was no single standard, there were more than fifty shades from light brown to orange. Over time, uniform requirements began to form. Today we will tell you about the size of basketballs, what they are made of, and also look at the most famous models.
The outcome of a duel depends on many factors. Not only the physical fitness and talent of the athlete, the form and surface on which the game takes place, determine the winner. The ball plays an important role. The trajectory of movement and adhesion to the surface depend on its quality, shape and size.
What are
There are several signs of classification. Everyone knows that basketball is not limited to the space of the hall, it can also be played on the street.
For each surface there are balls made of different materials. So, let's analyze the issue in more detail:
- INDOOR. Equipment of this nature can only be played indoors on a smooth surface. Features a soft surface. It should be noted that indoor is categorically not suitable for playing outdoors. Otherwise, you will simply waste your money, as the ball will quickly fail.
- OUTDOOR. Designed for playing on asphalt or hard ground. Made from synthetic materials. They are distinguished by a durable top layer, it does not wear out with frequent contact with a hard coating.
- Universal. Manufacturers claim that such balls behave equally well on any surface, but in practice this is not at all the case. Even if you saw the marking "INDOOR / OUTDOOR", pay attention to the material of manufacture. If the ball is made of rubber, then it is suitable for asphalt, and if made of leather, then be prepared that it will quickly deteriorate on the street. It is better to leave it for training on a wooden or rubber platform.
In order to figure out what size balls are in basketball, it is necessary to take into account the age and gender of the player. For example, a child who has just started training will not be able to play with an adult ball:
- For men. Their diameter averages 76 cm, weight - 600 gr.
- Women play with fewer implements. The average diameter is 73 cm, and the weight is 560 gr.
- Projectiles with a circumference of 70 cm and a weight of up to 500 g are intended for children.
In addition, this sports equipment is made of various materials:
- Rubber designed for training on hard asphalt surfaces. As a rule, they are inexpensive, but the service life is not long.
- Synthetic leather gear is resistant to all sorts of deformations and prevents air leakage. It is believed that such balls can be played both in the hall and on the street.
- Made of composite leather are perceived as an analogue of shells made of natural fibers.
Such inventory is soft, elastic. They can only be played on playgrounds made of wood and rubber. - Genuine leather shells are considered to be of the highest quality and durability. These are the balls that are played in competitions.
FIBA Standards
FIBA is an organization that unites all national basketball federations. It is she who determines the main directions of the development of world basketball. According to FIBA rules, the ball must meet six requirements. They concern weight, circumference, rebound and coefficient of friction.
The table shows FIBA standards:
US standards
In America, the standards differ slightly. Just like in FIBA, the weight of the ball in basketball should be in the optimal ratio with the age and gender of the player. So, for the NBA, shells with a circumference of 29.5 inches are suitable, and weighing 623 grams. The Women's League uses a 28.8" 567g inventory.
From 9 to 11 years old they use balls of 27 inches and 842 grams, and from 4 years old they start playing with shells of 25 inches and no more than 397 gr weight.
Ball pressure
This indicator is extremely important. After all, it directly affects the quality of the game. It is impossible to show good results both with an inflated and a deflated ball. Interestingly, FIBA does not have clear requirements regarding this issue. The only mention says that the projectile must be inflated to such a state that when it falls on the platform from a height of 180 cm, it bounces off approximately 130 cm in height.
Manufacturers
Be sure to look at the manufacturer when choosing a ball. It is known that companies with a name produce balls more expensive, but of high quality. We offer to consider several recognized leaders in the market for the production of the equipment in question:
- Spalding. It is this manufacturer that supplies shells for the games of the Major Basketball League and the Super League.
By purchasing such a ball, be sure that you have a quality product in front of you. - Wilson. The company became famous thanks to the Solution model. This ball is of excellent quality. A distinctive feature - absorbs moisture. It is worth noting that in Russia it is a great success.
- Nike. A company that is good in everything. Few people know that in addition to sportswear and shoes, Nike also produces balls. They are selected by the Euroleague and a number of basketball associations in the Philippines.
How much will it cost
Be prepared that the minimum price for a good accessory that will last more than one year starts from $30. So, for example, Wilson Evolution costs $50, and Nike Elite costs $48. Slightly cheaper, at $ 35, the simplest Spalding will cost.
What to look for when choosing
The projectile must be well inflated in order to bounce well off the surface. It's easy to check. Throw the ball to the floor with outstretched arms.
He should jump up to the waist. Or try putting your thumb on it. Ideally, it will bend by about 4 mm.
The shape also indicates the quality. There should be no bulges on the surface. Knock the ball, it should jump straight up straight, but not to the sides.
It is worth noting that the balls do not like dust and humidity. Therefore, play on a dry site, and then carefully clean the projectile from dust.
If you are a professional basketball player, it is better to purchase a high-quality projectile from leading manufacturers, made of modern synthetic materials.
Deciphering the marking
In order to understand exactly what kind of accessory is in front of you, it is important to understand the applied marking. So, the size will be indicated on the projectile:
Adult men and women play with balls of 6 and 7 sizes, size 5 is suitable for teenagers, and children who have just started playing need the smallest and lightest, at number 3.
