Answer:
m = 20 metric ton
Explanation:
Given,
The mass of the freight car, M = 10,000 kg
The velocity of the car before the collision, U = 105 km/h
The mass of another freight car, m = ?
The velocity of another freight car before the collision, u = 0 km/h
The velocity of the coupled car after the collision, V = 36 km/h
According to the conservation of momentum
MU + mu = MV + mV
mV = MU - MV ∵ mu = 0
m = M(U - V)/V
= 10,000 (108 - 36) / 36
= 20,000 kg
Hence, the mass of the another freight car is, m = 20,000 kg
