[填空题]
A person of mass 75 kg stands at t 27cc-j2 kh2zynkurz rex( 1b)he q(axcd 9o6p;t7w vul*center of a rotating merry-go-round platform of radius 3.0 m and momendu7 q c(v;t6w9p*xao lt of inertia 920 $kg \cdot m^2$ The platform rotates without friction with angular velocity 2 $rad/s$ The person walks radially to the edge of the platform. (a) Calculate the angular velocity when the person reaches the edge. $rad/s$ (b) Calculate the rotational kinetic energy of the system of platform plus person before and after the person’s walk.$KE_i$ = J $KE_f$ = J