Question

Take a bicycle rim and extend its axle on both sides. Tie two strings at both ends $A$ and $B$ as shown in the figure. Hold both the strings together in one hand such that the rim is vertical. If you leave one string, the rim will tilt. Now, keeping the rim in vertical position with both the strings in one hand, put the wheel in fast rotation around the axle with the other hand. Then, leave one string, say B, from your hand, and observe what happens. What will happen, if we leave string B?

• A. The rim will stop rotating
• B. The rim will rotate in a vertical plane and the plane of rotation will precesses about string A
• C. The rim will rotate in a horizontal plane
• D. None of the above

Answer 1

Answer: (B)

The rim keeps rotating in a vertical plane and theplane of rotation turns around the string A i.e., the axis of rotation of the rim or its angular momentum precesses about the string A