The kinetic energy of a rotating body is generally written as K=12Iω2, where I is the moment of inertia. Find the moment of inertia of the particle described in the problem introduction with respect to the axis about which it is rotating.

Respuesta :

Answer:

See explanation

Explanation:

We have a mass [tex]m[/tex] revolving around an axis with an angular speed [tex]\omega[/tex], the distance from the axis is [tex]r[/tex]. We are given:

[tex]\omega = 10 [rad/s]\\r=0.5 [m]\\m=13[Kg][/tex]

and also the formula which states that the kinetic rotational energy of a body is:

[tex]K =\frac{1}{2}I\omega^2[/tex].

Now we use the kinetic energy formula

[tex]K =\frac{1}{2}mv^2[/tex]

where [tex]v[/tex] is the tangential velocity of the particle. Tangential velocity is related to angular velocity by:

[tex]v=\omega r[/tex]

After replacing in the previous equation we get:

[tex]K =\frac{1}{2}m(\omega r)^2[/tex]

now we have the following:

[tex]K =\frac{1}{2}m(\omega r)^2 =\frac{1}{2}Iw^2[/tex]

therefore:

[tex]mr^2=I[/tex]

then the moment of inertia will be:

[tex]I = 13*(0.5)^2=3.25 [Kg*m^2][/tex]