Question

Which is more elastic: water or air, why?

Answer 1

Hint: We can solve this problem with the concept of elasticity and modulus. Elasticity is the ability of an object or material to resist a deforming influence and to regain its original size and shape when the force is removed. Elastic behavior can be different for the different materials. Modulus of the materials measures the amount of force per unit area needed for deforming an object. A higher modulus typically indicates that the material is harder to deform.

Complete step by step answer:
 A modulus is simply the ratio between the stress and strain. There are three types of modulus presents, Young’s modulus ,Shear modulus and Bulk modulus. Young modulus is the ability of material to change in the length when the force is applied along the length. Shear modulus is applied when there is force present in a transverse direction . Bulk modulus of a material is the ratio between the change in pressure and the resulting decrease in its volume Bulk modulus of material is reciprocal of compressibility.
Our question is which is more elastic water or air so applying these concepts in this question. Water is more elastic than the air because we know that the bulk modulus of elasticity is reciprocal of compressibility.

So the answer is water is more elastic than air because it is less compressible than the air.

Note: Thus we have given the reason for the elasticity of water and air with the help of bulk modulus. So the reason for more elasticity of water is more compressibility of water. Compressibility is a relative volume change of a fluid or solid when the pressure applies.