Pendulum Problem: Why Has It Stopped Oscillating?

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The pendulum stops oscillating because it is in freefall, eliminating the tension in the rope that normally provides centripetal force. When the elevator falls, the entire system, including the pendulum, accelerates downward at the same rate, disrupting the pendulum's motion. Without tension, the pendulum bob cannot follow its oscillatory path. Although the bob may have horizontal speed at the moment the cable breaks, it will not continue to oscillate. The key point is that the lack of tension in freefall prevents any further oscillation.
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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.
 
Thread 'Correct statement about size of wire to produce larger extension'

Thread 'Correct statement about size of wire to produce larger extension'

The answer is (B) but I don't really understand why. Based on formula of Young Modulus: $$x=\frac{FL}{AE}$$ The second wire made of the same material so it means they have same Young Modulus. Larger extension means larger value of ##x## so to get larger value of ##x## we can increase ##F## and ##L## and decrease ##A## I am not sure whether there is change in ##F## for first and second wire so I will just assume ##F## does not change. It leaves (B) and (C) as possible options so why is (C)...
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