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Inertigratus

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## Homework Statement

A sound wave with frequency 2 MHz is propagating through water and hits a ship hull made out of steel. The effective value (RMS?) of the acoustic pressure in water is 1kPa = P

_{0w}.

The acoustic impedance Z

_{w}for water is 1.46*10

^{6}and for steel Z

_{s}it is 4.03*10

^{7}. The wave propagation velocity is 1500 in water and 3800 in steel.

Find the amplitude (S

_{0}?) of the vibrations that the wave is causing through the steel hull.

## Homework Equations

I = P

_{0}

^{2}/2Z = (Z/2)*S

_{0}

^{2}*ω

^{2}

## The Attempt at a Solution

I have no idea how to do this. The only equation that seemed relevant to me is the one above. Perhaps the intensity is constant while the wave goes from water to steel?

If so, we could express the left part of the equation with the variables from when the wave is in the water and the right part with the variables from when it's in the steel hull.

I tried it though, and it's wrong :/

Ok, I think I figured it out... took some time. Had to calculate the transmitted intensity and then use the equation to the right to solve for the amplitude. Still a little off from the right answer, going to check the calculations again.

Well it's on the right magnitude atleast, I'm getting 3.8 * 10^-12 and it's supposed to be 5.4 * 10^-12. Any ideas?

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