# What is needed to allow sound to move an object

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1. Nov 18, 2015

### u0362565

I am interested to know what governs whether an object in the path of a sound wave will feel force. For instance will low frequency sound have more of an effect than high frequency? What difference does the material or shape of the object have on whether it would feel any force from the movement of the air. Would an object only feel force if the frequency matches the resonant frequency of the material?

Thanks for the help

2. Nov 18, 2015

### A.T.

3. Nov 18, 2015

### CWatters

No. However at resonance the object will usually absorb the most energy from the source.

4. Nov 18, 2015

### Ronie Bayron

Amplitude has some sort of effect, you could fit any wave with different amplitude at any given frequency

but, it would be a different issue when waves of the same frequency is out of phase 1800

Now which do you think would effect vibrations?

5. Nov 18, 2015

### Ronie Bayron

Also, sum of 2 waves in the same phase would result higher amplitude

6. Nov 19, 2015

### u0362565

7. Nov 20, 2015

### Staff: Mentor

I am fond of a more everyday example. When you are close enough to a fireworks display, you can feel the explosions thump against your chest.

Enrico Fermi famously dropped a bit of paper when he saw the flash of the Trinity test of the atomic bomb. As the shock wave of sound passed, the falling paper was blown away from the explosion. Then he measured the horizontal displacement of the paper where it hit the ground and he used that to estimate (fairly accurately) the yield of the explosion. Even though Fermi was a physicist, he is my all time favorite engineer.