A block of wooden 4"x4" timber is placed on an inclined plane and the angle of incline continually increased until the timber slides down, as seen in an mpeg video by clicking your mouse on the photograph at the left.
Now suppose that the experiment is repeated using the blocks seen in the photograph at the right above: rubber, styrofoam, and teflon (alphabetically, left to right). Which will begin to slide first and which last when the tilt of the incline is increased?
Rank the blocks in the order in which they will begin to slide:
Click here for Answer #133 after January 6, 2003.
