[填空题]
A 4.2-m-diameter merry-go-round i:av7qy;xr0g+wfs f,p yn:7 g+,jbv jqs rotating freely wia1 n:/;y iudr1en5els th an angular velocity of 0. yi;eu1snln1/5dear : 8 $rad/s$ Its total moment of inertia is 1760 $kg \cdot m^2$ Four people standing on the ground, each of mass 65 kg, suddenly step onto the edge of the merry-go-round. What is the angular velocity of the merry-go-round now? $rad/s$ What if the people were on it initially and then jumped off in a radial direction (relative to the merry-go-round)? $rad/s$