Every day, a train passes a train station along a straight line track, and the train moves at a constant speed.
Two friends, A and B, want to determine how long the train is. Lacking proper equipment, they devise the following method.
They first synchronize their walking. Both A and B walk at the same constant speed, and each step they take is the same length.
One day they line up back to back [met de ruggen tegen elkaar; HW] at the train station. When the front of the train reaches them, they both start walking in opposite directions.
Each person stops exactly as the back of the train passes by.
If person A takes 30 steps, and person B takes 45 steps, how long is the train, in terms of steps?
Dit alternatief werd ingebracht door een van de kijkers van deze video op YouTube:
Ok lets make this easy. When when A makes it to the back of the train B has been passed by two thirds of the train because he has walked 2/3 of his total distance at a constant rate relative to the train. (1/3 of the train still hasn’t passed B yet) We know the distance between A and B is 30+30 or 60 steps and that that is the remaining length of train yet to pass B. 1/3 train length = 60 steps 3/3 train length = 180 steps