Wood Center Groove Ruler
12 in / 30cm
Pencil Groove down the middle.
Binder Storage Holes
Standard / Metric
Metal Edge
Sold Individually
* This is the type ruler used in physics experiments with cups and marbles.

Newton's 2nd Law of Motion
Place one end of the ruler on an incline (book)
Rest the other end in a paper cup that you have cut a notch out of
Roll a marble down the middle of the ruler
- note the distance the cup moves.
Now, add a book to make the incline steeper and repeat...