The train was moving at a speed of 270 km / h and began braking with an acceleration

The train was moving at a speed of 270 km / h and began braking with an acceleration of -20 m / s. How long will it take for the train to stop?

To calculate the time interval during which the train in question was decelerated, we use the formula: t = (V – V0) / a, where V is the final speed (V = 0 m / s); V0 is the speed before braking (V0 = 270 km / h, in the SI system V0 = 75 m / s); a – acceleration (a = -20 m / s2).

Let’s make a calculation: t = (V – V0) / a = (0 – 75) / (-20) = 3.75 s.

Answer: The train in question should have stopped in 3.75 s.