Pendulum Problem: Why Has It Stopped Oscillating?

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Homework Help Overview

The discussion revolves around a pendulum's behavior, specifically why it stops oscillating when the system experiences freefall. The subject area includes concepts of mechanics, energy, and forces acting on the pendulum.

Discussion Character

  • Exploratory, Conceptual clarification, Assumption checking

Approaches and Questions Raised

  • Participants explore the relationship between tension in the rope and the pendulum's motion, questioning how freefall affects oscillation. Some inquire about the implications of the bob's kinetic energy and horizontal speed when the cable breaks.

Discussion Status

The conversation is ongoing, with participants offering insights into the mechanics of the pendulum and raising questions about the conditions under which it ceases to oscillate. There is no explicit consensus, but various interpretations of the problem are being examined.

Contextual Notes

Participants are discussing the effects of freefall on the pendulum's motion and the assumptions regarding the forces acting on it. The original poster seeks a thorough explanation, indicating a desire for deeper understanding.

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The answer to the attachment is that the pendulum has stopped oscillating. Why is this? Please explain this thoroughly to me, i would be very grateful of it. Thanks...
 

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The reason the pendulum oscillates is that there is tension in the rope holding it to the ceiling. The ball on the pendulum has potential energy and due to the tension in the rope will follow a pendulum path, however when the elevator falls, the entire system is freefall. There is no longer tension in the rope, because the entire system is falling at the same speed.

This is equivalent to holding a pendulum up, swinging it, and just letting go. Once there is no more tension in the rope, there is no centripetal force to keep it in motion.
 
Suppose the bob was at its point of highest kinetic energy when the cable broke. What will happens to the horizontal speed of the bob?
 
I'm really curious about this. Why does the bob stop? What happens to its horizontal speed?
 
quasar987 said:
I'm really curious about this. Why does the bob stop? What happens to its horizontal speed?

I think the question was only looking for whether it will still oscillate or not. So even though there might be a horizontal component of the velocity, it had stopped oscillating.
 

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