I kind of know what happens when you act with a centrifugal force upon a material object, but what about sound? For example, grabbing a phone who has music turned on and spinning it in the air? Thank you!
1 Answer
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The centrifugal force has nothing to do here. The term is also misused. We do not act with a centrifugal force about anything. Instead, it is correct to say that in our reference frame at rest we see rotating objects which experience a centripetal force, which can be friction, tension of a rope etc..
Sound is not an object, is a mechanical wave, a perturbation that propagates in a medium. In air, a vibrating object moves the nearby air molecules back and forth. They do the same job on the other adjacent molecules and so on. In this way, a pattern of compression and rarefaction is created. This is sound. So there is no centripetal force acting on it.
The phone rotates with a certain speed. It will produce a sound whose frequency is shifted according to the frequency it would produce if it was still. This is called Doppler effect. So you would just simply hear your music with a very slight Doppler shift, since the speed of the phone is small.
answered Mar 17, 2021 at 18:56