1. The problem statement, all variables and given/known data Train A travels with the velocity v= 30m/s, suddenly the driver sees another train ahead, Train B which travels with the velocity v=10m/s. Immediately Train A's driver starts the brakes ( a=1m/s²) while Train B still travels with its velocity. The moment A starts the brakes the distance between A's front and B's back is 200m. Will both trains collide? If yes, where? 2. Relevant equations v1=30m/s v2=10m/s a=1m/s² distance=200m 3. The attempt at a solution i searched the internet and found an equation: s= v² / 2a I was going to try it this way but ended up being confused. cause i wouldn't get metres out of it, instead seconds unknown person's attempt my attempt: s= 30m/s / 2*1m/s² = 30m/s * 1 / 2m/s² I don't know how to get a lenght out of this equation.