[填空题]
A ball of mass 0.440 kg moving east (+x direction) with a speed o; + o( 7tkum;c08lv h,pxe2mxt-6xnojqxsx,af p8n.tu.w8uv i collides head-on with a 0.220-kg ball at rest. If the collision is perfectly elastic, what will be the speed and direction of each ball after the collision?Let A represent the 0.440-kg ball, and B represent tpi u.8n8.vuw the 0.220-kg ball. $v'_A$ m/s $v'_B$ m/s
