Table of Mechanics Demonstration List of Mechanics Equipment & Supplies Lecture Demonstrations

# Tug-of-War, 1J30.21

Topic and Concept:

Location:

Abstract:

Two people pull in opposite directions on opposite ends of a rope demonstrating vector addition of the two opposing forces.

 Equipment Location ID Number Tug-of-War Rope ME, Bay B7, Shelf #2

Important Setup Notes:

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Setup and Procedure:

1. Lay the rope down in front of the audience such that it lays straight.
2. Obtain two or more volunteers to participate in a tug-of-war.
3. Have each volunteer or group grab an end of the rope and face each other.
4. Have each volunteer or group pull on the rope in the opposite direction of their competitor (this is the basic idea of tug-of-war).

Cautions, Warnings, or Safety Concerns:

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Discussion:

Each participant applies a force on the rope creating a tension in the rope. The tension is the sum of magnitude of each volunteer's inputted force. If each volunteer is equally matched (in the mathematical sense, admittedly a highly idealized situation), then the net acceleration of the system would be zero and the volunteer-rope system will not budge. Thus the match ends in a stalemate. Let's suppose the two volunteers are an offensive lineman from the Badgers varsity football team and an innocent, freshman physics major. It is safe to assume that the lineman can generate much more force than can his opponent. Thus the total force on the system is nonzero and there will be a net acceleration in the direction of the lineman. In other words, the lineman would win the match.

Videos:

References:

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