# HST24 Equilibrium of Parallel Forces

A force board is clamped into the HST1 Universal Frame and Stand (sold separately). Two acrylic models engraved to simulate a 'Warren' and an 'N' truss are used for the application of vertical loads and reactions. The forces are produced with cords tensioned by weights on hangers, double pulleys being used to turn the upward forces downward.

A circular disc with twelve attachment points is used for the couples. To simplify the results each acrylic model has a counterbalancing weight to render each one 'weightless'. The lines of action of the cords can be transferred onto a sheet of paper (not supplied) clipped to the force board. The set of weights needed for the experiment is included.

A comprehensive instruction manual for lecturer and student, giving full details on apparatus assembly and operation as well as example results. All necessary assembly and operational tools are provided.

Essential accessories: HST1

• Two acrylic models shaped and engraved to simulate a 'Warren' and an 'N' truss are used for the application of vertical loads and reactions
• A circular disc of Perspex provided to offer 12 peripheral attachment points for applying opposing couple.
• The forces produced by nylon cords tensioned by weights on hangers, pulleys being used to turn the cords vertically downward
• The lines of force to be transferred onto A1 paper sheet (not supplied) clipped to the force board
• Each Perspex model has a counterbalancing weight to render each one 'weightless'
• Must be used with HST1 universal Frame and Stand (sold separately)
• Comprehensive instruction manual provided
• 2 year warranty
• Verify the conditions of equilibrium when sets of parallel forces act in one plane on a rigid body
• ∑ Fv = 0 (where F = forces and V = vertical)
• Special case where equal and opposite parallel forces produce a couple acting on a body
• Equilibrium of opposing couples
• Experimental verification of the use of a link polygon and is a test of ∑M = 0 (where M = moments)