A uniform disk with a radius of 0.8 m and mass of 58.3 kg rotates at 5.4 rad/s. What is the rotational kinetic energy of the disk?

Question

Please send an answer and explanation ASAP I'm overcomplicating this question.

Answer 1

Let

r = 0.8 m be the radius of the disk,

m = 58.3 kg be the mass of the disk,

ω = 5.4 rad/s be the angular velocity.

The formula for rotational kinetic energy is

E = Iω²/2

where I is the moment of inertia.

For a uniform disk, the moment of inertia

I = mr²/2

Putting it together

E = mr²ω²/4

Substituting actual numbers

E = 58.3×0.8²×5.4²/4 = 272 J