Railroad car?

Question

1. A railroad car of mass 25000 kg is moving with a speed of 4 m/s. It collides and couples with three other coupled railroad cars, each of the same mass as the single car and moving in the same direction with an initial speed of 2 m/s. (a) What is the spee1. A railroad car of mass 25000 kg is moving with a speed of 4 m/s. It collides and

couples with three other coupled railroad cars, each of the same mass as the single

and moving in the same direction with an initial speed of 2 m/s. (a) What is the speed of four car after the collision? (b) How much energy is lost in the collision?

Answer 1

It is suggested that coupling be accomplished at or, preferably, below 4 mph to avoid damage to lading.

Answer 2

HOG  is right 5.6mph  will crack the in face of knuckle and damage the yoke