Perpendicular Forces
Safety Warnings
Warning: Structural Stability Warning
Purpose
A mass hangs from a string while a spring scale attempts to pull the string horizontal. Students see that no matter how hard they pull, the string cannot be made perfectly horizontal — demonstrating that infinite tension would be required, a direct consequence of vector force decomposition.
Figure 1:
The initial configuration shows the mass creating significant sag in the string. The force gauge reads approximately 24 N as the demonstrator attempts to pull the string horizontal.
Figure 2:
As the string is pulled closer to horizontal, the required force increases dramatically. Note that despite increased tension, a slight downward angle remains, demonstrating the impossibility of achieving perfect horizontality with finite force.