Magnetic Accelerator

This is a very popular science experiment, even the greatest minds will be captivated for hours.

This kit consists of:
-nine steel balls
-four nd 0500x0500 neodymium magnets
-hard wood channel

Some science experiment ideas:
-Distance between magnets vs Acceleration speed
-Number of steel balls between magnets vs Acceleration speed
-Alternating magnetic polarity between magnets, Outcome???
-Adding more balls or magnets, Outcome???