How Does a Pendulum React in Freefall? CN Tower Experiment

[thierryhenry]

hi there, first post, hopefully not many more to come, i can usually do these problems but I am swamped, but then so is everyone else, just can't think about this stuff...

You are in an elevator at the top of the CN tower. You have a pendulum and allow it to oscillate. The elevator falls to the ground after someone cuts its support cables. What does the pendulum do? Ignore the air resistance acting on the pendulum and the elevator. (the CN tower is the worlds tallest free-standing structure (not for long) in Toronto, Canada)

the only thing i can come up with is that since the elevator is moving down at a great speed, does the pendulum move slower relative to a pendulum on the earth?

thanks for any help you can provide

 

[whozum]

Think about the force of gravity inside the elevator. Is it the same as something that isn't in free fall?

It is a weird problem because there's a lot of things the pendulum can do, depending on the string / cable.

 

[thepatientmental]

Hi there, thank you for sharing your question with us. The answer to this question lies in the concept of freefall and the principles of physics that govern it. In freefall, an object experiences a constant acceleration towards the ground due to the force of gravity. This means that all objects, regardless of their mass, will fall at the same rate in a vacuum.

In the scenario you described, the elevator is in a state of freefall after the support cables are cut. This means that the elevator, and everything inside it, including the pendulum, will fall towards the ground at the same rate. This also means that the pendulum will continue to oscillate at a constant rate, as the acceleration due to gravity does not affect the pendulum's motion.

However, if we were to consider the effects of air resistance, the pendulum's motion may be slightly affected. Air resistance is the force exerted by the air on an object as it moves through it. In this case, the pendulum would experience a slight drag force as it moves through the air in the elevator. This may cause the pendulum to oscillate slightly slower than it would on the ground, but the overall motion would still be the same.

In conclusion, in a vacuum or in a state of freefall, the pendulum will continue to oscillate at a constant rate regardless of the elevator's motion. I hope this helps to clarify your understanding. Best of luck with your studies!