Question

The student investigates the speed of sound through wood. The density of wood is 0.90 g/cm3. What observation will the student make?


Sound travels faster through wood than through water or glass.


Sound travels slower through wood than through water or glass.


Sound travels faster through wood than through water but travels slower through glass.


Sound travels slower through wood than through water but travels faster through glass.

Answer 1

Sound speed depends on stiffness and density: v ≈ sqrt(elastic modulus / density). Solids are much stiffer than liquids, so wood transmits sound faster than water, but glass is stiffer still and transmits sound faster than wood.

So the correct choice is:
Sound travels faster through wood than through water but travels slower through glass.