Answer:
8.0 rad/s
Explanation:
I₁ = 1.0 kgm², ω₁ = -20.0 rad/s (clockwise is positive direction)
I₂ = 4.0 kgm², ω₂ = 15.0 rad/s
Angular momentum conservation:
I₁ω₁ + I₂ω₂ = (I₁ + I₂)ω
1.0 x (-20.0) + 4.0 * 15.0 = (1.0 + 4.0)ω
40.0 = 5.0ω
so ω = 8.0 rad/s
