[单选题]
When a light beach ball rolling with as s qyvdgy 50 4(b2y:/lpd4lp3likp2g speed of 6.0 m/s cofc)ovm +(f dc y(k;4)nl;ia pbllides with a heavy exercise ball at rest, the beacolaf;yn; mcpbc)( kv)f4+( i dh ball's speed after the collision will be, approximately,
