Question

A diver having a moment of inertia of 6.0 kg-m² about an axis through its centre of mass rotates at an angular speed of 2 rad/s about this axis. If he folds his hands and feet to decrease the moment of inertia to 5.0 kg-m², what will be the new angular speed ?

Answer 1

I₁ = 6 kg-m², ω₁ = 2 rad/s , I₂ = 5 kg-m²
Since external torque = 0
Therefore I₁ω​₁ = I₂ω_​2
ω₂ = (6 × 2) / 5 = 2.4 rad/s