Re: there is an experiment called

The experiment you describe depends on the same physics as the magician's
trick of pulling a tablecloth out from under a table set with plates,
silverware, cups, etc.  It works because of a principle called inertia,
which says that everything needs a force to cause it to move (or to stop
moving, too).  Some examples of forces are: gravity, which is a force that
makes objects move down toward the center of the Earth, and friction, which
is a force due to rubbing two things together and which can make things
slow down and stop.  You can read more about the law of inertia in a
physics text book such as College Physics by Franklin Miller (Chapter 3,
Dynamics, especially Newton's First Law, or the law of inertia).

The important point to remember is "forces cause motions:"
In your experiment, the bent broom provides a sharp, sudden force on the
plate, so the plate moves. Now, the friction between the plate and the
paper towel tube transfers enough of the broom's force to make the paper
towel tube move, too.  It sounds like in your experiment the friction
between the plate and the cup, though, is not strong enough to move the
cup, so it stays put.  Finally, the friction of the paper towel tube on the
golf ball is pretty small, so there's not enough force to make the ball go
sideways.  But, as soon as the paper towel tube is jerked away, there's
also no force holding the ball up, so the remaining force on the ball, the
force of gravity, makes it move down, and it falls neatly into the cup.  It
all works out because of the forces and how they act on each piece of the
experiment.