sound in water vs ice

[astronaut135]

Does sound travel faster in water or ice? I know that sound is supposed to travel faster in solids, but in this case ice is less dense than water so I'm not sure what happens. Anyone know? Thanks!

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[IlyaR]

Water is more dense and has a slightly higher bulk modulus, so it stands to reason that it would travel faster in water

 

[MCATMountain]

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[Razer]

The speed of sound in ice is nearly 3 times faster than in water.

The best way to conceptually approach the speed of sound in a medium is to think of the restoring forces (elasticity) and kinetic energy to be helping the sound wave, and any inertia (molecular mass) or extra density to be slowing down the sound wave.

In Ice, the molecules are trapped in a specific arrangement, making them VERY elastic (they will interact with a neighbor and snap back into place very quickly after they have been nudged by a sound wave), and speeding up the sound wave (this is why sound is faster in solids).

In water, the molecules aren't as elastic, and they are MORE dense. This means that more interactions between neighboring molecules are required for the sound wave to propagate a given distance (making it slower).

 

[FeinMS]

The speed of sound in ice is nearly 3 times faster than in water.

The best way to conceptually approach the speed of sound in a medium is to think of the restoring forces (elasticity) and kinetic energy to be helping the sound wave, and any inertia (molecular mass) or extra density to be slowing down the sound wave.

In Ice, the molecules are trapped in a specific arrangement, making them VERY elastic (they will interact with a neighbor and snap back into place very quickly after they have been nudged by a sound wave), and speeding up the sound wave (this is why sound is faster in solids).

In water, the molecules aren't as elastic, and they are MORE dense. This means that more interactions between neighboring molecules are required for the sound wave to propagate a given distance (making it slower).

I agree with this. Notice the Tension factor in speed of sound equation. Ice has more tension than water.

 

[BerkReviewTeach]

Water is more dense and has a slightly higher bulk modulus, so it stands to reason that it would travel faster in water

This is unfortunately the conclusion many people reach because they memorize a simple (and not always true) notion that speed of sound correlates with density. The reality is that there are many factors at play, and memorizing over-simplified ideology or random facts can actually be harmful to your MCAT score. The MCAT is a thinking exam and not a memorization exam.

The speed of sound in a medium correlates with the ability for the particles in the medium to be displaced and then returned to their original position. The faster they restore to their original position, the sooner they can transmit the next impact associated with the wave. Razer has done a great job elaborating on the factors involved. Particle speed and restoring forces acting on the particle increase the speed of sound while particle mass hinders the speed of sound.

 

[gettheleadout]

]This is unfortunately the conclusion many people reach because they memorize a simple (and not always true) notion that speed of sound correlates with density. [/B] The reality is that there are many factors at play, and memorizing over-simplified ideology or random facts can actually be harmful to your MCAT score. The MCAT is a thinking exam and not a memorization exam.

The funny thing about this is that simple memorization of the formula would have prevented the error in this case (http://hyperphysics.phy-astr.gsu.edu/hbase/sound/souspe2.html#c1). Unfortunately, even in the calculus-based physics course I took we were not exposed to this. We studied wave propagation, of course, but why this material was left out I have no idea, and it led myself and I'm sure others as well to infer that because sounds travels faster in iron than water and faster in water than air, sound speed is directly related to density. The case is in fact the inverse.

Why presenting this is so uncommon (in my experience) is beyond me.

 

[Gauss44]

The speed of sound in ice is nearly 3 times faster than in water.

The best way to conceptually approach the speed of sound in a medium is to think of the restoring forces (elasticity) and kinetic energy to be helping the sound wave, and any inertia (molecular mass) or extra density to be slowing down the sound wave.

In Ice, the molecules are trapped in a specific arrangement, making them VERY elastic (they will interact with a neighbor and snap back into place very quickly after they have been nudged by a sound wave), and speeding up the sound wave (this is why sound is faster in solids).

In water, the molecules aren't as elastic, and they are MORE dense. This means that more interactions between neighboring molecules are required for the sound wave to propagate a given distance (making it slower).

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