Determine the length of a train traveling at a speed of 40 km / h, sees within 3 seconds

Determine the length of a train traveling at a speed of 40 km / h, sees within 3 seconds an oncoming train 75 m long. At what speed is the oncoming train moving?

Initial data: V1 (speed of the first train) = 40 km / h; t (time of visibility of the oncoming train) = 3 s; S (length of the oncoming train) = 75 m.

1) Determine the speed of the oncoming traffic of two trains: V = V1 + V2 = S / t = 75/3 = 25 m / s (in km / h, this speed is 90 km / h).

2) Let’s calculate the speed of the oncoming train: V2 = V – V1 = 90 – 40 = 50 km / h.

Answer: The oncoming train will move at a speed of 50 km / h.



One of the components of a person's success in our time is receiving modern high-quality education, mastering the knowledge, skills and abilities necessary for life in society. A person today needs to study almost all his life, mastering everything new and new, acquiring the necessary professional qualities.