Concepts Of Physics MCQ Edition [Volume 1]
- Exam
- Concepts Of Physics MCQ Edition [Volume 1]
- Subject
- Physics
- Chapter
- Simple Harmonic Motion
Concepts Of Physics MCQ Edition [Volume 1] · Physics · Simple Harmonic Motion
Suspended from a nail in a wall, a closed circular wire experiences...
Suspended from a nail in a wall, a closed circular wire experiences small oscillations with an amplitude of 2^{}^{{}^{\circ}} and a time period of . Evaluate the acceleration of the particle on the wire farthest from the point of suspension as it passes through its mean position. Take .
Options
- A away from the point of suspension
- B towards the point of suspension
- C away from the point of suspension
- D towards the point of suspension
Correct answer
B. towards the point of suspension
Step-by-step solution
The moment of inertia of the closed circular wire (ring) about the point of suspension on its circumference is .
The distance of the center of mass from the point of suspension is .
The time period of the physical pendulum is given by:
Given and , we have:
The distance of the farthest point on the wire from the point of suspension is .
The amplitude of oscillation is \theta_0 = 2^{}^{{}^{\circ}} = 2 \times \dfrac{\pi}{180} = \dfrac{\pi}{90} \text{ rad}.
The angular frequency of the pendulum is .
The maximum angular velocity of the pendulum as it passes through the mean position is .
At the mean position, the angular acceleration is zero, so the tangential acceleration is zero. The acceleration of the farthest point is purely centripetal:
Converting to :
Using , we get .
The direction of this centripetal acceleration is towards the center of its circular path, which is the point of suspension.
Answer: towards the point of suspension
The distance of the center of mass from the point of suspension is .
The time period of the physical pendulum is given by:
Given and , we have:
The distance of the farthest point on the wire from the point of suspension is .
The amplitude of oscillation is \theta_0 = 2^{}^{{}^{\circ}} = 2 \times \dfrac{\pi}{180} = \dfrac{\pi}{90} \text{ rad}.
The angular frequency of the pendulum is .
The maximum angular velocity of the pendulum as it passes through the mean position is .
At the mean position, the angular acceleration is zero, so the tangential acceleration is zero. The acceleration of the farthest point is purely centripetal:
Converting to :
Using , we get .
The direction of this centripetal acceleration is towards the center of its circular path, which is the point of suspension.
Answer: towards the point of suspension