An aluminum block has thin rubber glued to its surface as seen in the photograph at the left below. When it is pulled along by a rope connected to a spring scale, the scale reads about 8 Newtons, as seen in an mpeg video by clicking your mouse on the photograph at the right below. Note that the spring scale is marked off in units of 2 Newtons.
Now suppose that a second aluminum block, shown in the photograph at the left, is placed on top of the original block, as seen in the photograph at the right. What will the scale read when the experiment is reproduced with the second block in place as shown?
With the second block in place, the scale will read:
Click here for Answer #151 after May 12, 2003.
