1J10.15 • Center of Mass: Irregular Objects

Location: Cabinet 1

Photo shows the demonstration used at the University of Texas at Austin.

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Concepts Conveyed:

This demo shows that the center of mass of an object does not have to physically be inside the object.

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Instructions/ Notes:

• (Optional) Have students guess where the center of mass will be, showing them the unmarked side.
• Hang the object (face the marked side towards students) on the provided stick through one of the three holes. Then, hang the mass on the stick in front of the object. The string will align with the markings on the object.
• Repeat this for the other two holes. The center of mass is where the three lines intersect. (This is because gravity acts on the center of mass.)
• To help students visualize where the center of mass will be, hold up the marked laminated paper behind the object.

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Demo Staff:

• Include a 50g mass (this can be found in Cabinet 4).

Last updated on September 10, 2026