Respuesta :
Answer:
The cars speed after the gravel is loaded, V = 4.44 m/s
Explanation:
Given data,
The mass of the railroad car, m = 20000 kg
The velocity of the railroad car, v = 6 m/s
The mass of the dropped gravel, m =7000 kg
The momentum of the railroad car,
P = mv
= 20000 x 6
= 120000 kg m/s
According to the law of conservation of momentum,
P = V (M + m)
V = P/ (M + m)
= 120000 / (20000 + 7000)
= 4.44 m/s
Hence, the cars speed after the gravel is loaded, V = 4.44 m/s
