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Basic Formula:
Speed = Distance / Time | Distance = Speed x Time | Time = Distance / Speed
Unit Conversion:
km/h to m/s → multiply by 5/18
m/s to km/h → multiply by 18/5
Crossing a Pole or a Person (stationary):
Time = Length of Train / Speed of Train
Crossing a Platform or Bridge:
Time = (Length of Train + Length of Platform) / Speed of Train
Two Trains — Same Direction (one overtaking the other):
Relative Speed = Speed of Faster Train − Speed of Slower Train
Time = (Length of Train 1 + Length of Train 2) / Relative Speed
Two Trains — Opposite Direction (coming towards each other):
Relative Speed = Speed of Train 1 + Speed of Train 2
Time = (Length of Train 1 + Length of Train 2) / Relative Speed
Train passing a moving person:
If person moves in same direction as train → Relative Speed = Train Speed − Person Speed
If person moves opposite to train → Relative Speed = Train Speed + Person Speed
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