A train crosses a pole in 10 seconds. If the length of the train is 100…
2025
A train crosses a pole in 10 seconds. If the length of the train is 100 meters, what is the speed of the train in km/hr?
- A.
34
- B.
36
- C.
30
- D.
32
Attempted by 1 students.
Show answer & explanation
Correct answer: B
Concept:
Speed = Distance ÷ Time. When a train crosses a stationary pole, the distance covered equals the train's own length. To convert speed from m/s to km/hr, multiply by 18/5 (i.e., 3.6); to convert km/hr to m/s, multiply by 5/18.
Application:
Distance covered while crossing the pole = length of the train = 100 m; time taken = 10 s.
Speed in m/s = Distance ÷ Time = 100 ÷ 10 = 10 m/s.
Convert to km/hr: 10 m/s × 18/5 = 10 × 3.6 = 36 km/hr.
Cross-check:
Reverse check: 36 km/hr × 5/18 = 10 m/s; distance covered in 10 s at 10 m/s = 100 m, which matches the train's length — confirming the speed.