9.4 The maximum ball spe
speed.
ed when hitting the racket and the bouncing ball
Above calculations have been based on maximum b l speeds when
with the racket, which is equal to 210
km/h or 58.3 m/sec [14]. While flying
the maximum boundaries of the
court th
e ball can travel over ≥23 meters
ded it travels along a straight line
parallel to the length of the court and not
less that around 32 meters provided it
travels diagonally. The sp
ed during the flight due to the air
resistance; therefore its initial speed
ld b higher [14].
We calculated the actual speed of the ball based on the theory of an object
(shell) flight in a resistance environment when shot at a certain angle from the surface
plane. – Figure 14.
The equation for movement in resistance environment is:
X = cosθ /b. h (Vo. cosθ /V cosθ),
where, Vo = Uo; V = U1; Rx = sir resistance
ρ = air density = 0.125 (at n
ormal temperature and humidity conditions and when
ured at the level of the court);
b1 – ball diameter = 0.065 m;
nce coefficient, which depends on the shape ;
0.14 for Re≤3.8 . 105 = 380000
π/4 = 0.0033 m2
For spherical shape it is Cx =
S – cross sectional area of the ball = 0.0652
