Question

Two ivory balls are placed together at rest. A third identical ball moving with velocity u in line of first two balls,as shown in figure collide head on elastically then(1)Third ball comes to rest with second ball while first ball moves with speed u(2) Third ball comes to rest and other two move together with speed(3) All three ball move together with speed(4) All three ball move in such a manner each makes angle 120° to each otherinthe floor then height​

Answer 1

third ball comes to rest with second ball while first ball moves with speed u