1. Where is it and What is it? Presented by Mark Wilson – RET 2009

2. ?  Purpose: to develop an understanding as to how interactions determine the existence of matter  Objective: BY INDIRECT MEANS, determine the size and shape of an unseen object using a rolling marble

3. Procedure  The white paper on top of each “cover” is a tracing platform  As you roll your marble under the cover, mark the entrance and exit points of the marble  Trace the approximate path of the marble on the paper with a pen/marker  Enough paths will help to “outline” the shape of the object ( NEVER TAKE PAPER OFF COVER)  Be sure to roll the marble from different angles/sides  XXXX  After your rolling, prepare your whiteboard

4. Whiteboard  Draw the shape of the object based on your results  Answer the following questions:  How was the speed of the marble a factor?  Discuss if marble size compared to the target size could size be a factor.  Why is it important to trace ALL paths?  Limitations/sources of error…