NEW ZEALAND PHYSICS TEACHERS' RESOURCE BANK

Rotational Inertia Wands

Translation:

Rotation:
Abstract
Students twirl equal mass wands, one with the mass at the ends and the other with the mass at the middle.
Portable Yes
Principles Illustrated
While the shape of an object is not important for translation, it is critical for rotation of an object.
NCEA & Science Curriculum
PHYS 3.4
Teacher Guide
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Instructions
Construct as shown in the photo of the apparatus. Have students verify that the force required to move the apparatus back and forth does not depend on the location of the masses, but the torque required to rotate the apparatus does. These are 1 Kg masses and the rod is from an equipment stand. Four clamps are required for each setup. A set of instructions for use by students is included under other materials below. Photo of the apparatus in use. This demo is used in Phys 114 Lab as a warm-up.
Safety

 

Be sure to use four clamps as shown here and here. The mass can slide into a student's hand and cause a nasty pinch if the inner clamp is omitted.
Individual teachers are responsible for safety in their own classes. Even familiar demonstrations should be practised and safety-checked by individual teachers before they are used in a classroom.
References
PIRA 1Q10.10
Worksheet for students
Instructions for students: Moving and Spinning.doc
Credits

This teaching resource was developed with support from
 
Copyright

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