[填空题]
A person of mass 75 kg;oy vy3a9v06uj ljl +v:gno cn0 :arf, stands at the center of a rotating merry-go-round platform of radius 3.0 m and moment of inertia 92ng:r nf:o ,ca00 $kg \cdot m^2$ 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
