Three masses m, 2m and 3m are moving in xy-plane with speeds 3u, 2u and u respectively, shown in the figure. the three masses collide at the same time at p and

Three masses m, 2m and 3m are moving in xy-plane with speeds 3u, 2u and u respectively, shown in the figure. The three masses collide at the same time at P and stick together. ' Ex. as velocity of the resulting mass would be he IT-JAM 2012