1. Geometry of the ride
We first consider motion in a horizontal plane,
without any tilting of the roof and use the photos
to analyse the motion. The radius or diameter of
the circle is always a relevant parameter in circular
motions: In this case the diameter, Dm, of the
circular motion of the swings in Himmelskibet
can be estimated from the photo in figure 1
through comparison with the diameter, Dr of the
circle of swings at rest, corresponding to the distance
across the central star (figure 4).
(i) Measure the size of the central star and the
diameter of rotation, Dm, for the swings
in motion the first photo in figure 1. Use
the ratio between them to estimate the
diameter for the moving swings using
the information that the central star is
Dr = 14 m across