[填空题]
A ball of mass 0.440w.mh 9d67,fj t o iwltmq3u8w) kg movingqx8a q8 n;wx ra:ymj: jem.4vs)ze2;t east (+x direction) with a speed of collides head-on with a 0.220-kg ball at rest. If the collision is perfectly elastic, what will b4rx8ytmxwn a8. aj;:qqj)mev; : zse2e the speed and direction of each ball after the collision?Let A represent the 0.440-kg ball, and B represent the 0.220-kg ball. $v'_A$ m/s $v'_B$ m/s