Question

A ring of mass 32 kg has an angular velocity of 110 rad/s.The radius of the ring is 0.380 m .What is the rotational kinetic energy of the ring?

Answer 1

Answer: 2.8 kJ

Explanation: Given that

The mass M = 32 kg

w = 110 rad/s

r = 0.380 m

Rotational kinetic energy = 1/2 Iw^2

Where I = moment of inertia

I = Σ mr^2

I = 32 × 0.38^2

I = 4.6208

Rotational K.E = 1/2 × 4.6208 × 110^2

Rotational K.E = 27955.84 J

= 2.8 KJ approximately