Physics

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a 32 kg child stands at the edge of a circular platform that rotates at w=2rad/s about its center. Mass of platform=60kg, radius=2m.
The child walks from the rim towards the center. Find the Angular speed when the child reaches a point 0.500 m from the center.

  • Physics -

    The law of conservation of angular momentum
    L₁ = L₂
    {(MR²/2) +(mR²)}ω₁ ={(MR²/2) +(mr²)}ω₂
    ω₂=ω₁{(MR²/2) +(mR²)}/{(MR²/2) +(mr²)}=
    =2{60•4/2 + 32•4}/(60•4/2+ 32•0.25}=
    =3.875 rad/s

  • Physics -

    Thank you!

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