To solve this problem it is necessary to apply the concepts related to Kinetic Energy, specifically, since it is a body with angular movement, the kinetic rotational energy. Recall that kinetic energy is defined as the work necessary to accelerate a body of a given mass from rest to the indicated speed.
Mathematically it can be expressed as,
[tex]KE = \frac{1}{2} I\omega^2[/tex]
Where
I = Moment of Inertia
[tex]\omega =[/tex]Angular velocity
Our values are given as
[tex]I = 0.039kg\cdot m^2[/tex]
A revolution is made every 4.4 seconds.
[tex]\theta = 1 rev \rightarrow 4.4s[/tex]
[tex]\Rightarrow \omega = \frac{1rev}{4.4s}[/tex]
If the angular velocity is equivalent to the displacement over the time it takes to perform it then
[tex]\omega = 0.2272rev/s(\frac{2\pi rad}{1rev})[/tex]
[tex]\omega = 1.42rad/s[/tex]
Replacing at our previous equation we have,
[tex]KE = \frac{1}{2} I\omega^2[/tex]
[tex]KE = \frac{1}{2} (0.039)(1.42)^2[/tex]
[tex]KE = 0.03993J[/tex]
Therefore the kinetic energy is equal to [tex]3.9*10^{-2}J[/tex]
