Static Torque Concept

Demonstrations in Static Torque

Hand gripping wooden cylindrical handle with thin metal rod extending left; a brass 1 kg mass hangs from a notch near the middle of the rod
Safety

Torque Bar

A volunteer holds a bar by its handle and tries to keep it horizontal while a 1 kg mass is hung from progressively farther notches. Students feel (or watch someone …
Seven wrenches arranged diagonally from smallest to largest on gray surface, including small combination wrenches and progressively larger adjustable wrenches up to a 24-inch model

Wrenches

A set of wrenches ranging from tiny to a 24-inch behemoth illustrates how lever arm length affects torque . The dramatic size progression makes mechanical advantage viscerally obvious.
Red-and-yellow checkered meter stick balanced on a black pivot stand, with a brass mass hanging from a screw clamp on the left and a larger black cylindrical mass on the right, mass set visible behind the pivot

Meter Stick on Support

Hanging different masses at different lever arm positions on a pivoted meter stick demonstrates torque balance. Students verify that at equilibrium and predict where to place masses to achieve balance.
Person standing on the overhanging end of an 8-ft wooden plank on a lecture bench; medicine ball and blue safety-stop blocks visible at the far end, chalkboard behind
Safety

Walking the Plank

A person walks along a plank extending over the edge of a lecture bench, dramatically illustrating torque balance. Adding a counterweight (medicine ball or lead bricks) to the opposite end …
Red-and-yellow meter stick supported horizontally by two large Ohaus 20N dial spring scales on vertical rods, with a brass mass hanging off-center from the stick. An Ohaus mass set sits on the green table below.

The Bridge Problem

A meter stick supported by two spring scales models a bridge: sliding a hanging mass along the stick shows how load position determines the force at each support. Demonstrates torque …
Red and yellow meter stick held horizontal by a bench clamp pivot at left end, with a string running from the stick up to a pulley at the top of the vertical rod and across to a large circular Newton force meter dial. A mass hangs from the right end of the stick.

The Derrick

Demonstrates the trigonometric dependence of torque and tension in static equilibrium. Students see how the tension in a support string changes with angle, and practice applying with adjustable geometry.
Four configurations of white Roberval balance with parallelogram linkage on wooden base, showing brass weights hung at various positions along the horizontal bars and outer arms

Roberval Balance

A parallelogram-linkage balance accurately compares masses regardless of where they sit on the pans — an apparent paradox resolved by analyzing the six pivot points. Suspending the balance from a …