[填空题]
In Problem 79 (Fig. 7–46), what idg krw hwnf/zyfdl9) 2yw:h 4q5lo(17s the upper lhhr xh4)p8-l0n3o/f pqb q *bpimit on mass m if it is to rebound from M, sh*3r)qpo- pnqbbhx p4fl0/ h8lide up the incline, stop, slide down the incline, and collide with M again? kg (Let A represent mass m, and B represent mass M.)
