Historians
can trace the early game of
tennis to a group of
thirteenth and fourteenth
century monks in Northern
France who struck a hard
wooden ball with the palms
of their hand.
It
wasn't until the sixteenth
century that rackets began
to be used and the game real
tennis was born.
Modern
tennis is officially
recognized to have been
invented by Major Walter
Clopton Wingfield in 1873.
After
a real tennis star J. M.
Heathcote invented a
bouncier rubber ball covered
in white flannel, "the
governing body of real
tennis, the Marylebone
Cricket Club (MCC),
established a new,
standardized set of rules in
1875 for tennis" [1].
"A number
of major innovations in
fashion and equipment
fueled and fed the boom
[in the late 1960s]. The
addition of color and
style to tennis wear (once
restricted to white)
created an entirely new
subdivision of leisure
clothing. Tennis balls,
which historically had
been white, now came in
several hues, with yellow
the color of choice.
Racket frames, which had
been of a standard size
and shape and constructed
primarily of laminated
wood, were suddenly
manufactured in a wide
choice of sizes, shapes,
and materials, the most
significant milestones
being the introduction of
metal frames beginning in
1967 and the oversized
head in 1976." [1]
Dimensions of a
Tennis Ball
The dimensions
of a tennis ball are "Diam. 6.5
cm, 57 g, hollow interior
construction and a cloth covered
exterior construction" [2]. Gravity Gravity is a Force
of attraction, so when you jump
into the air it is the Earth's
gravity that pulls you back
towards its core. Gravity
obviously acts the same way with
respect to a tennis ball and so it
can be concluded that without
gravity the game of tennis
would not be very fun, the ball
would never fall back into the
court if struck in an upwards
direction. A simple equation
can be given to describe this
force.
Fg = m*g
Newton's Laws
of Motion “Newton's
first
law states that every object
will remain at rest or in
uniform motion in a straight
line unless compelled to change
its state by the action of an
external force.”
“The second
law defines a force to be
equal to change in momentum
(mass times velocity) per
change in time."
F = m*a
“The
third
law states that for every
action (force) in nature
there is an equal and
opposite reaction.”
Each of these laws can be
applied to tennis in many
ways! A ball will not change
its trajectory,
incorporating drag and
gravity, until impacted by a
tennis racket. When a ball
hits the ground it does not
simply stop, instead it
compresses and springs back
into the air because the
ground is exerting a force
equal and opposite to the
force of gravity.
Friction "Frictional
resistance
to the relative motion of
two solid objects is usually
proportional to the force
which presses the surfaces
together as well as
the roughness of the
surfaces." [4] The
frictional force can then be
written.
Ff = uN
Where 'N'
is the normal force
pressing down or up on the
two objects, and 'u' is
the coefficient of
friction. Since there is
less friction present once
an object is moving, there
are usually two
coefficients of friction,
'uk' which is the
coefficient of kinetic
friction and 'us' which is
the coefficient of static
friction.
Drag
This
is a type of friction that
deals with objects moving
through fluids. If we
consider air as our fluid
and the tennis ball as our
object we can realize that
gravity is not the only
force acting on the ball,
and the way the ball spins
and forces air around it
will affect its
trajectory.
