# Crucial Substitution

**Classical Mechanics**Level 3

The motor Of an Electric Train can give it an acceleration of \(1 \text{ m/s}^{2}\) and It's brakes Can give it a negative acceleration of \(3 \text{ m/s}^{2}\). What is the shortest time in which the train can make a trip between two stations \(1215 \text { m} \) apart is?