🚀 go-pugleaf

my students perform a lab on the coefficient of restitution and
got  the  following  result:

                     wooden  floor           concrete  floor

tennis ball            0.65                     0.7

hard rubber ball        0.82                    0.81

soft rubberball         0.61                    0.60

super ball              0.94                    0.95

golf  ball              0.59                    0..85


based on the result ( several trials) there seem to be a very
strange finding.  Bouncing the balls on wooden floor, tennis
ball gets a higher coefficient of restitution compares to the
golf ball, yet on the concrete floor, the reverse is true.

A even more significant point is that for all other types of
balls, the differences for each type on the two surfaces  are
very  small,  yet
for the golf ball there is a very significant difference.

Can any one help figure out an explanation for such finding.

Thank  you


judy  ng