Answer:
ωf =1.78 rev/s
Explanation:
it is a non elastic collision, so conservation of angular momentum is used. and there id no friction
I₁ωi₁ + I₂ωi₂ = (I₁ + I₂)ωf
ωi₁ = 2.0 rev/s*(2π) rad/rev = 4.0π rad/s
assume ωi₂ = 0
Sol the equation to wf
ωf = (½m₁r₁²)ωi₁ / (½m₁r₁² + ½m₂r₂²)
ωf = (m₁r₁²)*ωi₁ / (m₁r₁² + m₂r₂²)
ωf = (5.0kg*(0.18m)²)4.0 π rad/s / ((5.0kg*(0.18m)²) + (3.1*(0.08m)²))
ωf =11.19 rad/s/ 2π
ωf =1.78 rev/s