(Hans Gijsen 2009 - now) By the rocker, the skate wil make a bend of its own at every inclined position to the ice.
Wich size is that bend?
The following equation gives a good approximation:
Rb = Radius of the followed bend.
Rs = Radius of the rocker.
a = the inclination angle of the skate to the ice surface.
Considering a standard rocker of 21m with the skate perpendicular on the ice.
The angle is 90 degrees. Cos a is than 0.
The bend the skate wil make has a radius tending to infinity. (skate goes fairly straight ahead)
Rb = 21 / 0 Dus Rb ---> infinity.
At an inclined angle of 60 degrees. Cos a is 0,5
Rb = 21 / 0,5 = 42m.
The skate wil make a bend of 42m.
At an inclined angle of 50 degrees. Cos a is 0,643
Rb = 21 / 0,643 = 32,7m.
The skate wil make a bend of 32,7m.
At an inclined angle of 45 degrees. Cos a is dan 0,707
Rb = 21 / 0,707 = 29,7m.
The skate wil make a bend of 29,7m.
At an inclined angle of 30 degrees. Cos a is dan 0,866
Rb = 21 / 0,866 = 24,2m.
The skate wil make a bend of 24,2m.
A racer does the 500m in 38s. Opening 10s, round 28s.
Mean speed during the 28s of the 400m round is 14,29 m/s, thats 51,4 Km/u.
During the bend a vectordiagram counts for the angle the skater makes to the ice surface.
tan a is: normal force / centripetal force. So tan a = m.g / (m.v^2 /Rb)
tan a = g.Rb / v^2
tan a = 9,81 . 25,5 / 14,29^2
tan a = 1,226
a = arctan 1,226 = 50,8 graden
a = the inclination angle of the skate to the ice surface.
g = gravitational acceleration 9,81 m/s^2
m = mass of the skater in Kg. (Striped away in the equation.)
v = speed of the skater in m/s. (v^2 is v square.)
Rb = Radius of the inner bend. 25,5m.
The inclination angle of the skater in the inner bend is 50 degrees.
Using rocker 21m, the skates wil make a mean bend of 32,7m.
The skater himself has to decide if the pushoff during that bend developes well.
Is it possible to give enough and controlled push off power untill the end of the stroke?
Does the skate run out of the bend to soon?
How many strokes do I make in one bend?
Is that what I want?