Suppose a 65 kg person stands at the edge of a 6.5 m diameter merry-go-round turntable that is mounted on frictionless bearings and has a moment of inertia of 1850 kg m2. The turntable is at rest initially, but when the person begins running at a speed of 3.8 m/s (with respect to the turntable) around its edge, the turntable begins to rotate in the opposite direction. Calculate the angular velocity of the turntable.

Respuesta :

Answer:0.316 rad/s

Explanation:

Given

mass of Person [tex]m=65 kg[/tex]

velocity of person [tex]v=3.8 m/s[/tex]

diameter of turntable [tex]d=6.5 m[/tex]

moment of Inertia of the table [tex]I_0=1850 kg-m^2[/tex]

Moment of inertia of Person I

[tex]I=mr^2=65\times (\frac{6.5}{2})^2[/tex]

[tex]I=686.56 kg-m^2[/tex]

initial angular velocity [tex]\omega _1=\frac{v}{r}[/tex]

[tex]\omega _1=\frac{3.8}{3.25}=1.17 rad/s[/tex]

Conserving Angular momentum

[tex]I\omega _1=(I+I_0)\omega _2[/tex] , where [tex]\omega _2=final\ angular\ velocity[/tex]

[tex]686.56\times 1.17=(686.56+1850)\times \omega _2[/tex]

[tex]\omega _2=\frac{686.56}{2536.56}\times 1.17[/tex]

[tex]\omega _2=0.316 rad/s[/tex]