A2L Item 184

• Description: Determine the acceleration of a hoop rolling down an incline.
• Goal: Problem solving with rotational dynamics
• Source: UMPERG-ctqpe148
• Keywords: Acceleration, Magnetic Field, Rotational Dynamics

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The question for students:

A hoop of mass 4 kg and radius 10 cm rolls without slipping down an incline 30° to the horizontal. The acceleration of the center of the hoop is most nearly

1. 10 m/s²
2. 5 m/s²
3. 3.5 m/s²
4. 2.5 m/s²
5. none of the above
6. cannot be determined

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Commentary for teachers:

Answer

(4) Students should realize that the acceleration must be less than a sliding mass on a frictionless surface would have which is #2. Engage the students in a discussion of why the acceleration cannot depend upon the radius.

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