After perfectly inelastic collision between two identical particles moving with same speed in different directions, the spee of the combined particle becomes half the initial speed of either particle. The angle between the velocities of the two before collision is

After perfectly inelastic collision between two identical particles mo

1.	After perfectly inelastic collision between two identical particles moving with same speed in different directions, the spee of the combined particle becomes half the initial speed of either particle. The angle between the velocities of the two before collision is
Answer» Solution :In perfectly inelastic collision between two PARTICLES, linear MOMENTUM is conserved. Let `theta` be the angle between the velocities of the particles before collision. Then `p^(2) = p_(1)^(2) + p_(2)^(2) costheta` or `(2m(v)/(2))^(2)=(MV)^(2)+(mv)^(2)+2(mv)(mv)costheta` or `1 = 1 + 1 + 2 COS theta or cos theta = - (1)/(2) , (or) thet a = 120^(@)`