Shop Mobile More Submit  Join Login
About Deviant a.k.wollapUnited States Recent Activity
Deviant for 4 Years
Needs Core Membership
Statistics 115 Deviations 283 Comments 34,559 Pageviews

Newest Deviations

no butts in line :iconwollap:wollap 58 8 a well oiled machine :iconwollap:wollap 57 9 cozy :iconwollap:wollap 45 5 yes :iconwollap:wollap 86 21 raridentity :iconwollap:wollap 133 40 copy pasta :iconwollap:wollap 105 19 ur :iconwollap:wollap 84 36 castles :iconwollap:wollap 108 18 yolk :iconwollap:wollap 59 11 the taste you can friendship :iconwollap:wollap 74 28 thanks :iconwollap:wollap 96 9 so fetch :iconwollap:wollap 67 8 fashion cents :iconwollap:wollap 135 26 spideys :iconwollap:wollap 102 30 superheroatmeal :iconwollap:wollap 69 18 shazam :iconwollap:wollap 69 19


Another M :iconpertheseus:Pertheseus 989 47 Pinkie EQG4 :iconiojknmiojknm:iojknmiojknm 435 8 Present. :iconmarenlicious:Marenlicious 1,207 61 Monster Musume is Magic! :iconfreedomthai:freedomthai 913 75 What a fashionable towel :iconsarmateppou:SarmaTeppou 233 11 Trixie being a silly horse :iconsarmateppou:SarmaTeppou 622 21 Comfy pony :iconsarmateppou:SarmaTeppou 481 13 To Your Knees :iconstepandy:StePandy 3,384 180 Who's A Silly Pony? S4 Ep13 and S6 Ep7 :iconthegreatrouge:thegreatrouge 457 77 Noxious Fleshborer :iconkotnonekot:KoTnoneKoT 182 4 The Legend of Zelda - redesign in Sci-Fi :iconmadmagnus:madmagnus 51 9 Best Friends - Request for dcencia :iconwandrevieira1994:wandrevieira1994 946 52 Everybody's New Dragon Waifu :iconmanual-monaro:Manual-Monaro 194 17 In Need of Nuzzles mk2 :iconcaptainpudgemuffin:CaptainPudgeMuffin 1,073 76 Princess of Laughter :iconyutaila:Yutaila 157 15 The Castle Isn't Open :iconsunbusting:SunBusting 770 28


no butts in line

Modern tennis balls must conform to certain criteria for size, weight, deformation, and bounce criteria to be approved for regulation play. The International Tennis Federation(ITF) defines the official diameter as 6.54–6.86 cm (2.57–2.70 inches). Balls must have masses in the range 56.0–59.4 g (1.98–2.10 ounces). Yellow and white are the only colors approved by the ITF, and most balls produced are a fluorescent yellow known as "optic yellow", first introduced in 1972 following research demonstrating they were more visible on television.

Tennis balls are filled with air and are surfaced by a uniform felt-covered rubber compound. The felt delays flow separayion in the boundary layer which reduces aerodynamic drag and gives the ball better flight properties. Often the balls will have a number on them in addition to the brand name. This helps distinguish one set of balls from another of the same brand on an adjacent court.

Tennis balls begin to lose their bounce as soon as the tennis ball can is opened. They can be tested to determine their bounce. Modern regulation tennis balls are kept under pressure (approximately two atmospheres) until initially used; balls intended for use at high altitudes have a lower initial pressure, and inexpensive practice balls are made without internal pressurization. A ball is tested for bounce by dropping it from a height of 254 cm (100 inches) onto concrete ; a bounce between 135 and 147 cm (53 and 58 inches) is acceptable—if taking place at sea-level and 20 °C (68 °F) with relative humidity of 60%; high-altitude balls have different characteristics when tested at sea-level.

i am a brilliant


wollap's Profile Picture
United States


Add a Comment:
Doctor-Derpy Featured By Owner Sep 2, 2016  Student Filmographer
Happy birthday! :D
nautiical Featured By Owner Sep 1, 2016  Hobbyist Digital Artist
hap birth
Streled Featured By Owner Sep 1, 2016   Traditional Artist
Happy birthday.
PickleEbony Featured By Owner Sep 1, 2016  Student Digital Artist
Happy Birthdayy Birthday cake  icon 
Rose150 Featured By Owner Sep 1, 2016  Hobbyist Digital Artist
happy birthday!
HurricanestarPegasus Featured By Owner Sep 1, 2016   General Artist
Happy Birthday?
HellArmy Featured By Owner Sep 1, 2016  Hobbyist General Artist
Merry Christmas! Santa Clause 
VanillaGhosties Featured By Owner Sep 1, 2016  Hobbyist Digital Artist
Hepy Burday!
CuteToyBonnie Featured By Owner Sep 1, 2016
Happy Birthday !
Mailinya Featured By Owner Sep 1, 2016  Hobbyist Digital Artist
Happy birthday! birthday cake 
Add a Comment: