A 250-kg moose stands in the middle of the railroad tracks in Sweden, frozen by the lights of an oncoming 10,000kg train traveling at 20m/s. Even though the engineer attempted in vain to slow the train down in time to avoid hitting the moose, the moose rides down the remaining track sitting on the train’s cowcatcher. What is the final velocity of the train and moose after the collision? (Momentum & Impulse)

The final velocity of the train and the moose after collision is approximately 19.51 m/s

Explanation:

The given mass of the moose, m₁ = 250 kg

The velocity of the moose, v₁ = 0

The mass of the oncoming train, m₂ = 10,000 kg

The velocity of the train, v₂ = 20 m/s

The velocity of the moose and the train after collision = v₃

By the principle of conservation of linear momentum, the total initial momentum before the collision = The total final momentum after collision

m₁·v₁ + m₂·v₂ = (m₁ + m₂)·v₃

Therefore, by substitution, we have;

250×0 + 10,000× 20 = (10,000 + 250) × v₃

200,000 = 10,250 × v₃

v₃ = 200,000/10,250 ≈ 19.51 m/s

The final velocity of the train and the moose after collision = v₃ ≈ 19.51 m/s