Question

Why is the speed of longitudinal waves sound in solids greater than that in liquids?

(a) Solids have lesser bulk modulus

(b) Gases have lesser density

(c) Solids have greater bulk modulus and density than gases but increase in bulk modulus dominantes over increase in density

(d) Gases don’t have lesser particles in a given volume and therefore transfer sound energy slowly

Answer 1

Correct option is (c) Solids have greater bulk modulus and density than gases but increase in bulk modulus dominantes over increase in density

Easy explanation: Speed is expressed as √(B/ρ).  

For solids B and ρ is greater than that of gases but an increase in B compensates over the increase in ρ,                                                                                                                                and thus speed is greater in solids.