Answer:
V₂ = 1.5 m/s
Step-by-step explanation:
given,
speed of the first piece = 6 m/s
speed of the third piece = 3 m/s
speed of the second fragment = ?
mass ratios = 1 : 4 : 2
fragment break fly off = 120°
α = β = γ = 120°
sin α = sin β = sin γ = 0.866
using lammi's theorem

A,B and C is momentum of the fragments

4 x V₂ = 2 x 3
V₂ = 1.5 m/s