Q.

Three equal masses m are kept at vertices (A, B, C) of an equilateral triangle of side a in free space. At t = 0, they are given an initial velocity VA=V0AC,VB=V0BA and VC=V0CB. Here AC,CB and BA ware unit vectors along the edges of the triangle. If the three mases interact gravitationally, then the magnitude of the net angular momentum of the system at the point of collision is :         [2025]

1 12amV0  
2 3amV0  
3 32amV0  
4 32amV0  

Ans.

(3)

tan 30°=2ra=13  r=a23

Net angular momentum about point O

L=(mvr)×3=mv0a23×3=32mv0a