  Studies of spicules and similar solar jets reveal a strong correlation
between some of the kinematic variables, particularly between the initial
velocity V, and the subsequent deceleration, a. It has been proposed that there
is a linear relationship between these two variables and that this offers proof
for a shock wave mechanism acting on the spicules, although the linear
equations found are all different. It is shown here that the relationship is
better described by a non-linear form: V is proportional to the square root of
a. This relationship between V and a also provides a simple physical
interpretation for the results. The different linear equations are found to be
simply tangents to this (a,V) curve. Another method used to investigate the
(a,V) connection is to determine the correlation coefficients between the
kinematic variables from their scatter plots . It is also shown how these
correlations also can be predicted from the mean value of the acceleration and
height and their standard deviations for the sample under consideration. The
implications of these results and the possibility that spicule behaviour is
partly due to magnetic fields are discussed.
