Northwestern Physics Demos                                 Go back to Mechanics
DCS# 1F20.10NWU# M-28Location: 1C3
title: Inertia Ball
aka: Breaking string

Frame holds up a massive ball hung by a string.  The bottom of the ball is attached to a level by more of the same type string.    When the lever is pressed slowly, the top string breaks, but when it is pressed rapidly, the bottom breaks.  The inertia of the ball protects the top string from the rapid increase in tension, but not from the slower increase.

  Which string will break?  (take a vote?)
  Explain to your neighbor why the bottom string broke.
set up [ix