[填空题]
What is the angular momentum of a 0.210-kg ball rotating on thritrmv7cpn /1 /;ziyl bvvx 99g-1k /ue end of a 6;q fufk9 n 8bu.1pfxpm,z: 2cnk 2eh gn-8aahthin string in a circle of radi2h;,zn 6kpgn uf8bc8 :qmx9pau- fan2.1 kehfus 1.10 m at an angular speed of 10.4 $rad/s$? $kg \cdot m^2$