Magnetic Accelerator

Can you guess how fast the steel balls will roll and why they accelerate? A magnetic accelerator ... Buy it:
$26.95 at Fat Brain Toys
Ullman Devices Corp. ULLHT-3 Magnetic Pick-Up T...

Featured Stores:
$9.32 at ToolTopia.com
Ullman Devices Corp. ULLHT-2 Magnetic Pick-Up T...

Featured Stores:
$10.59 at Tools Plus