SCIENCE IN BASKETBALL
HANGTIME
HOW HIGH SOMEONE JUMPS DEPENDS ON THE FORCE USED TO PUSH ON THE FLOOR WHEN STARTING TO JUMP, WHICH DEPENDS ON HOW STRONG YOUR LEGS ARE. THE STRONGER THE JUMP THE LONGER AND HIGHER THE HANGTIME IS. IF YOU JUMP FOUR FEET YOUR HANGTIME WOULD BE 1.0 SECONDS. THIS IS A PICTURE OF MICHAEL JORDAN HANGTIME. HE WAS NICKNAMED AIR JORDAN BECAUSE OF HIS LONG PERIODS OF HANGTIME.
HOW HIGH SOMEONE JUMPS DEPENDS ON THE FORCE USED TO PUSH ON THE FLOOR WHEN STARTING TO JUMP, WHICH DEPENDS ON HOW STRONG YOUR LEGS ARE. THE STRONGER THE JUMP THE LONGER AND HIGHER THE HANGTIME IS. IF YOU JUMP FOUR FEET YOUR HANGTIME WOULD BE 1.0 SECONDS. THIS IS A PICTURE OF MICHAEL JORDAN HANGTIME. HE WAS NICKNAMED AIR JORDAN BECAUSE OF HIS LONG PERIODS OF HANGTIME.
PASSING
WHEN PASSING THE BALL FROM ONE PLAYER TO ANOTHER, THE BALL IS CARRIED BY MOMENTUM- THE PRODUCT OF MASS AND VELOCITY OF AN OBJECT. WHEN A PLAYER IS MOVING FAST AND HE/SHE PASSES THE BALL IT IS GOING TO GO FARTHER AND STRONGER THAN IF THE PLAYER WAS SLOWING DOWN OR STANDING STILL.
DRIBBLING
WHEN A PLAYER DRIBBLES, THE KINETIC ENERGY FROM HIS OR HER MUSCLES TRANSFERS TO THE BALL. THE HARDER THE PLAYER BOUNCES THE BALL, THE HIGHER THE BALL WILL GO, BUT GRAVITY WILL ALWAYS BRING IT BACK DOWN TO THE EARTH.
THE JUMP SHOT
WHEN SHOOTING A JUMP SHOT, A PLAYER SHOULD RELEASE AT THE TOP OF THE JUMP, WHEN THEIR VELOCITY IS ZERO. THIS GIVES THEM MORE CONTROL.
THE SHOES
PLAYERS SHOULD WEAR SHOES WITH GOOD FRACTION TO CREATE FRICTION, THE FORCE THAT OPPOSES THE MOTION OF TWO SURFACES THAT ARE IN CONTACT. THIS HELPS PLAYERS QUICKLY PIVOT AND GRIP THE FLOOR SO THEY WON'T SLIP OR SLIDE.
NEWTON'S THREE LAWS WITH EXAMPLES
LAW #1- EVERY OBJECT IN A STATE OF MOTION TENDS TO REMAIN IN MOTION UNTIL AN EXTERNAL FORCE IS APPLIED.
EXAMPLE- A JUMP SHOT WILL INITALLY MOVE UPWARD UNLESS ACTED UPON BY THE FORCE OF GRAVITY.
LAW #2- THE RELATIONSHIP BETWEEN AN OBJECTS MASS, M, ITS ACCELERATION, A, AND THE APPLIED FORCE, F, EQUALS F=MA.
ACCELERATION AND FORCE ARE VECTORS; IN THIS LAW, THE DIRECTION OF THE FORCE VECTOR IS THE SAME AS THE DIRECTION OF THE ACCELERATION VECTOR.
EXAMPLE- THE HARDER YOU THROW THE BALL (THE MORE FORCE), THE MORE ACCELERATION THE BALL WILL HAVE.
LAW #3- FOR EVERY ACTON THERE IS AN EQUAL AND OPPOSITE REACTION.
EXAMPLE- WHEN YOU SHOOT THE BALL, AND IT MAKES CONTACT WITH THE RIM, IT RICOCHETS OFF.
EXAMPLE- A JUMP SHOT WILL INITALLY MOVE UPWARD UNLESS ACTED UPON BY THE FORCE OF GRAVITY.
LAW #2- THE RELATIONSHIP BETWEEN AN OBJECTS MASS, M, ITS ACCELERATION, A, AND THE APPLIED FORCE, F, EQUALS F=MA.
ACCELERATION AND FORCE ARE VECTORS; IN THIS LAW, THE DIRECTION OF THE FORCE VECTOR IS THE SAME AS THE DIRECTION OF THE ACCELERATION VECTOR.
EXAMPLE- THE HARDER YOU THROW THE BALL (THE MORE FORCE), THE MORE ACCELERATION THE BALL WILL HAVE.
LAW #3- FOR EVERY ACTON THERE IS AN EQUAL AND OPPOSITE REACTION.
EXAMPLE- WHEN YOU SHOOT THE BALL, AND IT MAKES CONTACT WITH THE RIM, IT RICOCHETS OFF.
PHYSICS OF BASKETBALL
YOU WOULD USE LIFT TO REBOUND THE BALL AND ACCELERATION TO CATCH UP WITH SOMEONE OR STEAL. BASKETBALL ENVOLVES VELOCITY, ANGLE, HAND-EYE COORDINATION, AND BALANCE TO SHOOT. YOU WOULD ALSO USE PROPER FINGER AND WRIST CONTROL OF THE BALL, AND ARC OF SHOOTING. YOU NEED TO USE BACKSPIN TO 'SOFTEN' THE BASKETBALL SHOT. FORCE ON THE BALL TO PASS OR SHOOT. GRAVITY BRINGS YOU AND THE BALL DOWN.
KINETIC ENERGY
WHEN YOU BOUNCE THE BALL YOU ARE CREATING KINETIC ENERGY. WHEN YOU TOSS THE BALL YOU ARE ALSO TRANSFERRING KINETIC ENERGY FROM YOUR MUSCLES TO THE BALL.
ANGLE
YOU CAN WEIGH THE BALL THEN MEASURE THE DISTANCE YOU NEED TO THROW IT. WITH THAT DATA YOU COULD CALCULATE THE EXACT POWER AND LAUNCHING ANGLE YOU NEED TO USE. THE PROBLEM IS THAT YOU MUSCLE CONTROL IS IMPERFECT. IT IS NOT POSSIBLE FOR HUMANS TO REPLICATE THE SAME MOVEMENT OVER AND OVER LIKE A ROBOT MIGHT. BUT, WITH PRACTICE, YOU CAN IMPROVE.
HIGH ARC
THE PERFECT SHOT SWISHES, MEANING IT DOESN'T TOUCH THE BACKBOARD OR RIM. THE HIGHER YOU ARE THE BETTER CHANCE YOU HAVE OF SWISHING. PRACTICE LAUNCHING THE BALL HIGH SO IT DROPS RIGHT THROUGH THE NET. AS YOU GET STRONGER YOU CAN SHOOT FROM FARTHER OUT, LIKE THE THREE POINT LINE. IF YOU HAVE GOOD ARC IT IS VERY HARD TO BLOCK YOUR SHOT.
WHEN YOU SHOOT...
WHEN YOU SHOOT YOU ARE BASICALLY DOING A MENTAL CALCUATION AND DECIDING THREE THINGS.
1) HOW FAR AWAY IS THE RIM- VERTICALLY AND HORIZONTALLY?
2) HOW FAST DOES THE BALL NEED TO BE WHEN IT LEAVES MY HAND?
3) WHAT IS THE BEST ANGLE FOR THIS SHOT?
1) HOW FAR AWAY IS THE RIM- VERTICALLY AND HORIZONTALLY?
2) HOW FAST DOES THE BALL NEED TO BE WHEN IT LEAVES MY HAND?
3) WHAT IS THE BEST ANGLE FOR THIS SHOT?
IN A BASKETBALL
THE OUTSIDE COVERING IS MADE OF SYNTHETIC RUBBER, RUBBER COMPISITION, OR LEATHER. THE INSIDE CONSISTS OF A BLADDER, (THE BALLOON-LIKE STRUCTURE THAT HOLDS THE AIR) AND THE CARCASS. THE BLADDER IS MADE OUT OF BUTYL RUBBER AND THE CARCASS IS MADE OF TREADS OF NYLON OR POLYESTER. PRE-PRINTED DECALS ARE USED TO LABEL BALL, OR FOIL IS USED TO IMPRINT LABEL INFORMATION.
MAKING A BASKETBALL
- Forming the bladder
- 1 The making of a basketball begins with the interior bladder. Black butyl rubber in bulk form (and including recycled rubber) is melted in the hopper of a press that feeds it out in a continuous sheet that is 12 in (30.5 cm) wide and 0.5 in (1.3 cm) thick. A guillotine-like cutter cuts the long strip into sheets that are 18 in (45.7 cm) long, and they are stacked up. A hand-controlled machine selects the sheets one at a time and, using a punch press, punches a 1-in-diameter (2.54-cm-diameter) hole that will hold the air tube for inflating the bladder.
- 2 The sheets are carried on a sheet elevator or conveyor to an assembly line where the air tube is inserted by hand. A heated melding device bonds it to the sheet, which is folded into quarters. Another punch press stamps out a rounded edge and, at the same time, binds the edges to make the seams of the bladder. This bladder is not perfectly shaped.
- 3 The odd-shaped bladder is taken to a vulcanizing machine. Vulcanization is a process for heating rubber under pressure that improves its properties by making it more flexible, more durable, and stronger. In the vulcanizer, the bladder is inflated. Heating by vulcanization uniformly seals the rubber so it will hold air. Completed bladders are stored in a holding chamber for 24 hours. This quality control measure tests their ability to hold air; those that deflate are recycled.
- 4 The bladders that withstand the 24-hour inflation test are conveyed from the holding chamber to the twining or winding department. They make this joumey suspended from a conveyor system by their air tubes. Machines loaded with spools of either polyester or nylon thread or string wrap multiple strands at a time around each bladder; this is the same process used to make the inside of a golf ball. The irregularly shaped bladders now begin to take on a better, more rounded shape as the precisely controlled threads build and shape the balls. The quality of the thread and the number of strands determine the cost and quality of the ball. The typical street-quality basketball has a carcass made of multiple wraps of three strands of polyester thread. The balls used by professional teams have carcasses constructed of nylon thread that is wrapped using four strands of thread. The same over-head conveyors continue carrying the carcass-encased bladders by their air tubes to the next step in the process where the carcasses and covers will meet.
- 5 Meanwhile, the exteriors or covers of the balls have been in production as the bladders and carcasses have taken shape. On 60-inch-long (152-cm-long) tables, colored rubber is unrolled from a continuous roll. The smooth rubber does not have pebbling (small bumps) that characterizes the surface of a finished basketball so that the outlines for the panels can be clearly marked on the rubber. A silk screen is moved along a series of metal markers that are guides marking the length of the rubber sheet needed for each ball. The silk screen operator moves the screen by hand and imprints the outlines of the six panels making up the ball. Only one color is used at a time, and, depending on the design, multiple silk screenings may be needed to color the six panels with all the colors on the ball.
- 6 A hand-operated punch press—equipped with specially designed and tooled dies—punches the rubber outlines to create six separate panels per ball. The same die has a hole that is punched in one of the six panels to make an opening for the air tube. The excess rubber surrounding the panels is lifted off the line and deposited in a bin for recycling.
- 7 The assembly worker picks up the six panels for a single ball in a specific order and carries them to the vulcanizer. The interior of the vulcanizer for this process is different from the one for the bladders. It is form-fitted to hold the six panels, to create the channels between the panels, and to add any embossed information. The assembler fits the panels individually into specified sections in the vulcanizer. A bladder/carcass is taken off the overhead conveyor, covered with a coating of glue, and placed inside the chamber of the vulcanizer that is lined with the cover panels. When the ball emerges from the vulcanizer, most of its surface is still smooth (there are no bumps, called pebbling), but the channels and any embossing are formed into the surface.
- 8 Decals and foil decoration and information (if any) are applied by hand with small heat presses after the smooth ball is retrieved from the vulcanizer. Each ball is carefully inspected for gaps between the panels. These can occur, but each gap is filled during this inspection with a small piece of rubber that is hand-cut to fit the gap. The ball then is fitted into another vulcanizer that unifies the finished surface, blending in any gap fillers, and is specially molded to form the surface pebbling. The vulcanized balls are stored again for 24 hours in a second test to make sure they hold air.
- 9 The covers for basketballs that are made of synthetic laminated rubber or leather are also made in panels that are die-cut like the rubber panels. The synthetic laminated panels are shaved or trimmed along the edges, fitted and glued together by hand, and laminated to the carcass to create channels. They are also embossed by a heating process and decals are added. Any glue traces around the edges are removed, and any imperfect panels are replaced in the final inspection of synthetic laminated covers. Leather covers are made of full-grain, genuine leather and are stitched with heavy-duty machines; instead of indented, formed channels, the stitching forms the channels in leather balls. They are printed by silk screening and foil stamping, and their inspection includes a review of the uniformity and color of the leather.
- 10 Balls that pass the second 24-hour air pressure test are "bounce tested" to meet the regulation for inflation pressure that results in each ball bouncing a prescribed height. Balls that pass the bounce test are numbered to show the production run, and the decals and other artwork are inspected and touched up by hand as needed. Each completed ball is inspected again. The inspector removes the production run tag, and the ball is deflated so it can be easily packed and shipped. Each flattened ball is packed in a polyethylene bag, and the bagged balls are boxed for bulk shipment to the distributor. The distributor also inspects the balls when they are received and is responsible for reinflating them to the correct pressure and packaging them in display boxes for sale. The display boxes may also be packed in bulk for distribution to retailers.