Board slide/ Friction

The first time we lifted the board and took our measurements the board was unfinished, in other words- not sanded. These were our results the first time, the rock went at 10 inch, the wood went at 12 inch, the eraser went at 19 inch, and the ice cube went at 23 inch. (we guessed the eraser would have been last but we think the ice cube melted to the wood... we call this experimental error!) After we sanded the board we did the experiment again, and these were our measurements- the rock, piece of wood, and the ice cube went at 12 inch, and the eraser went at 15 inch.

1- the paper fell slowly, the book fell fast! 2- the book and paper fell equally fast! Because we put the paper on top of the book, the book has a bigger mass so it does not get slowed down by the influence of Gravity!