Animation

t = 4.23 (slider from 3.7 to 5.7, step 0.01)
l = 4 (slider from 0 to 7, step 0.05)
g: 12.0 / sqrt(l)
A = Point(xAxis)
B = Point(xAxis)
a = Line(A, B)
C = Point(a)
c = Circle(C, l)
P: (l * cos(t), l * sin(t))
b = Segment(C, P)
D = (4, -5)
E = (4, -1)
F = (11, -5)
G = Point(a)
H = Point(a)
d = Segment(G, H)
Gewichtskraft = 4 (slider from 1 to 4, step 0.1)
Q: (x(P), y(P) - Gewichtskraft)
u = Vector(P, Q)
e = OrthogonalLine(P, b)
f = Line(P, b)
h = Line(Q, e)
i = Line(Q, f)
I = Intersect(e, i)
J = Intersect(h, f)
v = Vector(P, I)
w = Vector(P, J)
j = Segment(I, Q)
k = Segment(Q, J)