IDNLearn.com provides a seamless experience for finding the answers you need. Find the answers you need quickly and accurately with help from our knowledgeable and experienced experts.

Find the moment of inertia about the y-axis of the thin semicirular region of constant density

Sagot :

The moment of inertia about the y-axis of the thin semicircular region of constant density is given below.

[tex]\rm I_y = \dfrac{1}{8} \times \pi r^4[/tex]

What is rotational inertia?

Any item that can be turned has rotational inertia as a quality. It's a scalar value that indicates how complex it is to adjust an object's rotational velocity around a certain axis.

Then the moment of inertia about the y-axis of the thin semicircular region of constant density will be

[tex]\rm I_x = \int y^2 dA\\\\I_y = \int x^2 dA[/tex]

x = r cos θ

y = r sin θ

dA = r dr dθ

Then the moment of inertia about the x-axis will be

[tex]\rm I_x = \int _0^r \int _0^{\pi} (r\sin \theta )^2 \ r \ dr \ d\theta\\\\\rm I_x = \int _0^r \int _0^{\pi} r^3 \sin ^2\theta \ dr \ d\theta[/tex]

On integration, we have

[tex]\rm I_x = \dfrac{1}{8} \times \pi r^4[/tex]

Then the moment of inertia about the y-axis will be

[tex]\rm I_y = \int _0^r \int _0^{\pi} (r\cos\theta )^2 \ r \ dr \ d\theta\\\\\rm I_y = \int _0^r \int _0^{\pi} r^3 \cos ^2\theta \ dr \ d\theta[/tex]

On integration, we have

[tex]\rm I_y = \dfrac{1}{8} \times \pi r^4[/tex]

Then the moment of inertia about O will be

[tex]\rm I_o = I_x + I_y\\\\I_o = \dfrac{1}{8} \times \pi r^4 + \dfrac{1}{8} \times \pi r^4\\\\I_o = \dfrac{1}{4} \times \pi r^4[/tex]

More about the rotational inertia link is given below.

https://brainly.com/question/22513079

#SPJ4