JEE Main202529 Jan 2025Evening ShiftPhysicsRotational MotionActual
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 V _A=V₀ A C , V _B=V₀ B A and V _C=V₀ C B . Here, A C , C B and B A are unit vectors along the edges of the triangle. If the three masses interact gravitationally, then the magnitude of the net angular momentum of the system at the point of collision is :
Options
- A3 a m V ₀
- B3 2 a m V ₀
- C3 2 a m V ₀
- D1 2 a mV ₀
Correct answer
C. 3 2 a m V ₀
Step-by-step solution
d= a 2 3 Angular momentum of one mass about point O aligned L & =m v d & =m v₀ a 2 3 aligned Net angular momentum about point O aligned L_ net & =32 & = 3 m v₀ a 2 aligned