Question

What is the modulus of rigidity of an incompressible liquid and value of young's modulus for a perfectly rigid body

Answer 1

The Young's modulus for perfectly rigid body is   Infinity because the value of change in length is zero,

ΔL=0

We know that,

young's modulus can be expressed as,

Y.M=Stress/Strain--- >A)

Strain is equal to ΔL/L

put Strain's value in eq A)

then ,

Y.M=stress/ΔL/L

Y.M=L*stress/ΔL

when ΔL is zero then Y.M would be infinity so that Young's modulus of a rigid body is Infinity.

What is the modulus of rigidity of an in compressible liquid (It is Zero because it is hard to compress)