| The following mathematics deals with the X,Y
and Z axis within the confines of a Roulette Wheel environment.
Y axis¦N1¦*COS(a)-(mg)*COS(a)=0
X axis¦N2¦+¦N1¦*SIN(a)+¦mg¦*sin(@)*COS(Y)=m*¦@ centre)=m*V^2/R=m*[Y')^2]*R
V=Linear Velocity
R=Ball Track Radius
@=Centripedal acceleration
Z axis¦Ffr¦+¦Air Drag¦=m*¦@tan¦=m*Y''*R
Friction Force a This is negative as it is opposing the Z axis
Air Drag is the force that is equal too:
¦Air Drag¦= - 0.5*CD*P*TT*r^2*V^2 (TT is pie) this is also a minus
value!
CD is Drag Coefficiaent
P is AIr density
r is the balls Radius
Z axis is always tangentially directed.
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After some very simple Algerbraic Transformation and incorporating
the above formulas we get the next differential equation:
Y''=(a+air*R)*(Y')^2=b*SIN(Y)+c*COS(Y)+d (*)
Where
a is the determining friction factor(Ie 0.004)
Air =-[0.5*CD*P*TT*r^2*V^2]/m
b=a*g*SIN(@)/R
c=b/a
d=a.g.COS(@)SIN(a)+1)/(R.COS(@)
The ball movement sters to this equation only till the moment when it
loses the contact with the vertical side of the ball track or:
[N2]=0
So the Drop off condition is:
[(Y')^2]*R+g*COS(@)*tg(a)-g*SIN(@)*COS(Y)=0 (**)
Now lets introduce some real values into the equations and see the
predicted results:
TT=3.14
g=9.807
R=0.4
a=16.7.TT/180 inner slope of stator
CD=0.47
r=0.5.21.10^-3 Radius of ball
P=1.22
m=9.10^-3 Mass of Ball
(a)= 0.004 Friction factor for rolling between the ball and the track
@=0.8 grad Tilt Angle
t0= 0 sec
t1=30 seconds
These values determin the time interval of 30 sec since the start of
spinning!
I also calcualted the time the ball loses contact with the vertical
wall of the ball track, this is when(**) becomes true!
Time till drop off is 17.04 seconds
By this time the ball passes 4935 Grad or 13.7 revolutions from start
point!
At this moment the ball has a velocity of 2.7 Rads/Sec or 0.43 Revs
per/Sec!
SEE FURTHER>
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