This Bankers Tutorial article is independent educational material. Examples are illustrative, and changing rules or examination requirements should be checked at the official source.
01 / UNDERSTANDING
Understand the idea
The front of a train reaching a marker does not mean the train has passed it. Tracking the rear as well as the front explains the full-length distance in a simple physical picture.
02 / UNDERSTANDING
The concept in context
A train passes a point only after its full length clears that point. Passing a platform requires travelling the train length plus platform length. When two trains pass each other, use their combined length with relative speed: add speeds for opposite directions and subtract for the same direction under the stated constant-motion assumptions.
Keep length and speed units compatible. Multiplying kilometres per hour by five eighteenths converts to metres per second. A diagram of the front and rear positions often clarifies the required distance. Relative motion describes how one object closes on another and should not be confused with either train’s own speed relative to the ground.
03 / UNDERSTANDING
A worked learning case
Original educational case. An original 150-metre train moves at 54 km/h, equal to 15 m/s. Passing a pole takes 150/15 = 10 seconds. Clearing a 150-metre platform takes 300/15 = 20 seconds, because both lengths must pass the same reference edge. The speed is unchanged; the event definition changes the required distance.
ORIGINAL EDUCATIONAL PRACTICE
Try it before you check.
Original practice: A 120 m train travels at 36 km/h. How long to pass a pole?
Show the answer and reasoning
12 seconds.
Convert 36 km/h to 10 m/s using 5/18. To pass a pole, the train travels its own 120-metre length, so time is 120 ÷ 10 = 12 seconds. No platform length is supplied or required. Using kilometres per hour directly with metres would create incompatible units and an incorrect result.
Two traps to watch for.
- Adding platform length when the reference is only a pole.
- Using ground speed instead of relative speed for two moving trains.
YOUR TOPIC-SPECIFIC LEARNING MAP
Turn understanding into practice
Identify exactly what must be cleared.
Convert speed and length to compatible units.
Choose sum or difference for relative speed.
Explain the idea, apply it to a new situation, then check what changed in your reasoning.
BANKERS TUTORIAL · SOURCE NOTES
Keep the source alongside your notes.
Official links provide subject context and authoritative reference material. This guide’s explanation, scenario and question are original Bankers Tutorial learning content.
- www.ibps.in https://www.ibps.in/
- www.ibps.in https://www.ibps.in/index.php/faq/
For IBPS & RRB preparation, check the current official notice before relying on changing dates, rules or examination requirements.
