Given,
A 42,000 kg train car travelling at 10 m/s toward a stationary train car with a mass of 40,000 kg.
Momentum is a product of the mass of a particle and its velocity. Momentum is a vector quantity which means it has both magnitude and direction. Its formula = mass × velocity.
Solve for momentum:
M= (42,000kg)(40,000kg) / (10m/s)
M = 42,000 kilograms - 40,000 kilograms
M = 2,000kg
M = 2,000 kg ÷ 10m/s
= 200m/s
-Thus they collison at the same speed of 200m/s.
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