$3-8.$ A flywheel is a uniform disk of radius $R$ and thickness $t$ and is made

of a material of mass density $.$ Write the constitutive law for the $1-$

port representing the flywheel in its flow$-$momentum form. Evaluate the

inertance parameter for a steel disk $1$ in$.$ in thickness and $10$ in $.$ in diameter.

Provide your answer as an Equation and a Block Diagram.