Answer: [tex]0.43\ rad/s[/tex]
Explanation:
Given
Mass of child [tex]m=34\ kg[/tex]
speed of child is [tex]v=2.8\ m/s[/tex]
Moment of inertia of merry go round is [tex]I=510\ kg.m^2[/tex]
radius [tex]r=2.31\ m[/tex]
Conserving the angular momentum
[tex]\Rightarrow mvr=I\omega \\\Rightarrow 34\times 2.8\times 2.31=510\times \omega\\\\\Rightarrow \omega=\dfrac{219.912}{510}\\\Rightarrow \omega=0.43\ rad/s[/tex]