Why does sound travel faster through hot water?

Answer 1

equation for speed of sound in a medium:

c=sqrt(B/rho)

B=bulk modulus

rho=density

all else being constant, and increase in temperature will cause an expansion (usually) of the material. The expansion will decrease the density (mass per unit volume) and thus increase the speed of sound through the material.

Answer 2

Sound travels faster in hot water because higher temperature increases the speed of sound waves due to the increased kinetic energy of the water molecules. This results in a faster propagation of sound through the medium, compared to colder water where molecules move at a slower pace.