Answer:
their final velocity is 0.091 m/s
Explanation:
Given;
mass of the first train, m₁ = 138,000 kg
mass of the second train, m₂ = 123,000 kg
initial velocity of the first train, u₁ = 0.288 m/s
initial velocity of the seocnd train, u₂ = -0.131 m/s (opposite direction to the first)
Let their common final velocity after been coupled = v
Apply the principle of conservation of linear momentum;
m₁u₁ + m₂u₂ = v(m₁ + m₂)
(138,000 x 0.288) + (-0.131 x 123,000) = v(138,000 + 123,000)
39,744 - 16,113 = v(261,000)
23,631 = v(261,000)
v = 23,631 / 261,000
v = 0.091 m/s
Therefore, their final velocity is 0.091 m/s
