TennisTennis is a racket sport that is played either individually against a single opponent (singles) or between two teams of two players each (doubles). Each player uses a tennis racket strung with a cord to strike a hollow rubber ball covered with felt over or around a net and into the opponent's court. The objective is to manoeuvre the ball in such a way that the opponent is not able to play a valid return.
Real tennisReal tennis – one of several games sometimes called "the sport of kings" – is the original racquet sport from which the modern game of tennis (also called "lawn tennis") is derived. It is also known as court tennis in the United States, royal tennis in the United Kingdom and Australia, and courte-paume in France (to distinguish it from longue-paume, and in reference to the older, racquetless game of jeu de paume, the ancestor of modern handball and racquet games).
Drag (physics)In fluid dynamics, drag, sometimes referred to as fluid resistance, and also known as viscous force, is a force acting opposite to the direction of motion of any object moving with respect to a surrounding fluid. This can exist between two fluid layers, or between a fluid and a solid surface. Drag forces tend to decrease fluid velocity relative to the solid object in the fluid's path. Unlike other resistive forces, drag force depends on velocity.
Flow separationIn fluid dynamics, flow separation or boundary layer separation is the detachment of a boundary layer from a surface into a wake. A boundary layer exists whenever there is movement between a fluid and a solid surface. Viscous shear forces are present in the layer of fluid close to the surface. Boundary layers can be either laminar or turbulent.
MassAmount of matter present in an objectMass is an intrinsic physical quantity of a body which in modern physics is generally defined as the strength of an object's gravitational attraction to other bodies. The unit of mass in the International System of Units (SI) is the kilogram (kg). Mass can also be understood as a measure of the energy content of a body (see E=mc²).Boundary layerLayer of fluid in the immediate vicinity of a bounding surfaceThe boundary layer around a human hand, schlieren photograph. The boundary layer is the bright-green border, most visible on the back of the hand (click for high-res image).In physics and fluid mechanics, a boundary layer is the thin layer of fluid in the immediate vicinity of a bounding surface formed by the fluid flowing along the surface.
Nitrogen–↑N↓Pcarbon ← nitrogen → oxygen
OxygenChemical element with atomic number 8 (O)–↑O↓Snitrogen ← oxygen → fluorine
Wimbledon ChampionshipsAnnual tennis tournament held in LondonThe Wimbledon Championships, commonly called Wimbledon, is a tennis tournament organised annually in Wimbledon, London, by the All England Lawn Tennis and Croquet Club in collaboration with the Lawn Tennis Association. It is chronologically the third of the four Grand Slam tennis events each year, held after the Australian Open and the French Open and before the US Open.World TennisWorld Tennis, known as the International Tennis Federation (ITF) until June 2026, is the governing body of world tennis, wheelchair tennis, and beach tennis. It was founded in 1913 as the "International Lawn Tennis Federation" by twelve national tennis associations. As of 2026, there are 214 national and six regional associations that make up the World Tennis membership.
FeltFelt is a textile that is produced by matting, condensing, and pressing fibers together. Felt can be made of natural fibers such as wool or animal fur, or from synthetic fibers such as petroleum-based acrylic or acrylonitrile or wood pulp–based rayon. Blended fibers are also common. Natural fiber felt has special properties that allow it to be used for a wide variety of purposes.Professional sportsIn professional sports, as opposed to amateur sports, participants receive payment for their performance. Professionalism in sport has come to the fore through a combination of developments. Mass media and increased leisure have brought larger audiences, enabling sports organizations and teams to command large incomes.
Amateur sportsAmateur sports are sports in which participants generally compete without receiving payment for their participation. The distinction is made between amateur sporting participants and professional sporting participants, who are paid for the time they spend competing and training. In many sports which feature professional players, professionals generally compete at a higher level than amateur competitors, although the distinction is not universal.*As an Amazon Associate I earn from qualifying purchases.