
C11: In the
17th century, Otto von Guericke, the mayor of Magdeburg, Germany, fitted two hollow bronze
hemispheres together and removed the air from the resulting sphere with a pump.
Two eight-horse teams could not pull the halves apart even though the
hemispheres fell apart when air was readmitted. Suppose von Guericke
had tied one team of horses
to one side and bolted the other side to a heavy tree trunk. In this case, the tension
on the hemispheres would be
1.
twice
2.
exactly
the same as
3.
half
what it
was before.
