A man riding a bicycle at 90 km/hr crosses a bridge in 37 minutes. Find the…
2026
A man riding a bicycle at 90 km/hr crosses a bridge in 37 minutes. Find the length of the bridge.
Answer: C. 55.5 km — ConceptFor motion at a constant speed, distance equals speed multiplied by time: Distance = Speed × Time. All quantities must use compatible units before the…
- A.
57.9 km
- B.
62.5 km
- C.
55.5 km
- D.
65.6 km
Attempted by 75 students.
Show answer & explanation
Correct answer: C
Concept
For motion at a constant speed, distance equals speed multiplied by time: Distance = Speed × Time.
All quantities must use compatible units before the formula is applied.
Application
Treat the rider and bicycle as a point object, so the distance travelled while crossing is the bridge length.
The speed is 90 km/hr and the time is 37 minutes.
Convert the time to hours: 37 minutes = 37/60 hour.
Apply the relation: Distance = 90 × (37/60) km.
Simplify: Distance = (90/60) × 37 = 1.5 × 37 = 55.5 km.
Cross-check
At 90 km/hr, the distance covered in one minute is 90/60 = 1.5 km. In 37 minutes, the distance is 1.5 × 37 = 55.5 km, which agrees with the main calculation.
Therefore, the bridge is 55.5 km long.