why do some tennis balls have a number 2 on them, while others have a number 3? whats the difference?
478453
The numbers on the balls are only there to help people distinguish their balls from another can of the same brand on an adjacent court. \n\nNumbers on the tennis balls are right under the logo. This is so that when you have, say, 8 adjacent courts and some are using the same brand or type of ball, then there won't be a mix-up of someone's ball sprays onto the other court. Unless, of course, they're both using the same number tennis balls. For instance, if you are using Penn 3s, the court on your left has Penn 1s, and the court to your right has Wilson 3s, you can tell at a glance which court to throw the extra ball to and in turn they can get your lost ball to you easier.
462449
Around 56g-58g.\n\nA tennis ball is hollow and composed of inflated rubber, covered with a fabric which must be uniform. Its between 2 1/2 and 2 5/8 inches (6.35 and 6.67 cm) in diameter and weighs between 2 and 2 1/16 ounces (57.7 and 58.5 grams). Yellow and white balls are used in competition. When dropped on concrete from a height of 100 inches (2.5 meters), they must bounce upward from 53 to 56 inches (135 to 147 centimeters). The serve is the most important stroke in tennis.\n\nLitell, Mifflin. Integrated Mathematics. Evanston, IL: 1995. "Ball (tennis), Diam. 6.5 cm, 57 g, hollow interior construction and a cloth covered exterior construction" 57 g \nTennis. Americana Online. "The ball is a cloth-covered rubber sphere that is generally yellow in color, approximately 2 1/2 inches (6.35 cm) in diameter and 2 ounces (56.69 grams) in weight" 56.69 g \nSports A to Z: Tennis: Equipment. United States Olympic Committee. "A tennis ball is hollow and composed of inflated rubber covered with a fabric. It is between 2 1/2"and 2 5/8"(6.35 and 6.67 cm) in diameter and weighs between 2 and 2 1/16 ounces (57.7 and 58.5 grams)." 56.7 - 58.5 g \nNew Encyclopedia Britannica. 15th ed. 1997. "The ITF specifies that the ball must be between 2 1/2 inches (6.35cm) and 2 5/8 inches in diameter and between two ounces (56.7 g) and 2 1/16 ounces in weight" 56.7 g \nWorld Book Encyclopedia. Chicago: World Book, 1998. "It must weigh more than 2 ounces (56.7 grams) but less than 2 1/16 ounces in weight" 56.7 - 58.5 g
42484
When tennis was created, the point system they used was modeled after the hands on a clock. So the first point was 15 the next was 30, then 45. After a while, people shortened the 45 to just 40. Some times when I play I even hear people say 5 instead of 15. \n\nAnd incase you are wondering about where name “Love” the tennis term for zero, came from, you have to go to France. The French word for egg, which looks like the number zero, is oeuf and “oeuf” was used a slang for zero.  Oeuf then became “love” by English speaking players over the years.
456402
It is the soft-nest of the ball.  So someone with a rather soft swing would want a 1-3 and a hard hitter would want a 3-6.  Also the temperature has a lot to do with this.  On hot days i prefer a harder ball but on cool days i take a soft ball.  (it has nothing ot do with telling them apart, it is just convenient)
670469
The numbers refer to the players involved in the play.\n(e.g. 6-4-3 double play, would be a ball hit to the shortstop (6), thrown to the second baseman (4) for the first out, and then to the first baseman (3) for the second out.)\n\nThe complete list:\n1 - pitcher\n2 - catcher\n3 - 1st base\n4 - 2nd base\n5 - 3rd base\n6 - shortstop\n7 - left field\n8 - center field\n9 - right field
380851
i think you might have yahoo answers confused with your magic eight ball.\n\n//
349908
Usually these numbers have recurred in a persons life several times, and they associate them with good things.  For instance, a child may say 5 is his lucky number because that was his number while playing t-ball.  Once you "pick" a lucky number, you tend to notice it in a good context for a very long time.  The truth is, it could be any number.
721850
I was under the impression that they were different size balls. But this guys says they are the same. Check out these links.
1013311
according to the International Tennis Federation the official diameter as "more than" 2 and1/2 inches but "less than" 2 and 5/8 inches. The weight is "more than" 2 ounces but "less than" 2 and 1/16th ounces
214481
The answer to your question starts with understanding the scoring system.  1. Most tennis matches are comprised of best 2 out of 3 sets.  2. A set is whichever player accumulates 6 "games" first and wins by 2 games.  If the score reaches 6 games to 6 games then a tiebreaker "special game is played to decide the set.  Each "game in tennis" is comprised of points which are 15, 30, 40, game.  Or as you pointed out 4 points, win by two, for each game.  The reason each game is not scored by 1,2,3,4, is so not to confuse the set score.  So if someone asked you what the present score was you would not say its 2 points to 2 and the set score is 2 to 2 also.  In tennis you would say its 30 all and 2 games each.  Simple, with no confusion.  The reason games are scored 15, 30, 40 game is because it is like hands on a clock. 40 actually represents the 45 minute mark but it had too many syllables so they reduced it to 40. When the clock reaches the Top or one full revolution, that constituted "a game."  This was how the system originated and shows their logic behind it.
1143750
Pool if you knock in the strip or solid then thats what you are during the whole game until you are going for the 8 ball. 9 ball is just using the balls 1 through 9 and you have to knock them in order and saving the 9 ball for last. Who ever knocks in the 9 ball out of order loses.
289916
The number of dimples on a golf ball varies, depending on the manufacturer and may even be different for different models made by the same manufacturer. The dimples are usually the same size as one another, but some golf balls have several different sizes of dimple on the same ball. Any number between 300 and 500 dimples is reasonable, and 336 is a common number.
210105
First Round: 8 balls Second Round: 10 balls Third Round: 16 balls Final Round: 11 balls
347016
Normally 336, but anywhere between 300 and 500 is acceptable. Different balls have different numbers of dimples.
1044074
Maybe the referee just got confused between 2 and 3.
1167251
Tennis racquets are of a somewhat oval shape while racquetball racquet are much shorter and have a flattened top.\n\nPicture of a tennis racquet:\nhttp://www.ideal.co.nz/site/ideal/images/stickandwin/19_Ultra_LT_Tennis_Racket_WITRCS510.jpg\n\nPicture of a racquetball racket:\nhttp://www.racquetworld.com/merchant2/graphics/product_pictures/racquets/triadt170sm.jpg\n\nWhile a tennis racquet could be used in a game of racquetball, a real racquetball racquet should be used if you have any desire to pursure the game any further. \n\nGo ahead and play a game of racquetball with your friend using tennis racquets, but beware that prolonged use of them in a racquetball game could damage them. Racquetballs are much heavier than a tennis ball and could cause frame fractures and/or damage to the strings. \n\nIt's ok to improvise, but use the equipment designed for the game if you do it frequently.\n\nEDIT:In response to the ball part, you can use a tennis ball if you would like, if the place where you go to play allows it. My local YMCA did not allow tennis balls in the raquetball courts. Again, don't use a tennis ball if you are playing with people other than your friends, as a tennis ball would not be allowed on any sort of competitive level.\n\nNot your question, but you shouldn't do the reverse - that is use a raquetball on a tennis court. The surface of a (hard court) tennis court is very rough and would damage the rubber raquetball very quickly.
103046
I feel I can answer this question well because I've not only been a tennis player for the last 37 years, I'm also a Mechanical Engineer as well as a nationally certified  tennis instructor.\n\nThe connection of the racquet's shaft to the racquet's head affects the location of the sweet spot. And, it's always better to have the sweet spot located further from the direction of the grip because you gain greater leverage and, therefore, more power.\n\nSince the shaft has the tendency to move the sweet spot in the wrong direction (away from the head and closer to the grip), the racquet designers make the head oval, instead of circular, to overcome this tendency. Indeed, the elongation of the oval head returns the sweet spot to a position higher on the head thereby restoring power.