[填空题]
A 0.060-kg tennis ball,l5ki2 k8havo 9 moving with a speed of 2.5m sw0a3/twp a kgd9vb-5/s collides head-on with a 0.090-kg ball initially moving away from it at a speed of 1.15m/s Assuming a perfectly elastic collision, what are the speed and direction of each ball a k -/wgs bvwa359t0adpfter the collision?(Let A represent the 0.060-kg tennis ball, and let B represent the 0.090-kg ball.)v'$_A$ = m/s v'$_B$ = m/s