A cyclist travels at a constant speed of 48 km/h and takes 26 minutes to cross…
2026
A cyclist travels at a constant speed of 48 km/h and takes 26 minutes to cross a bridge. Assuming the cyclist's length is negligible, find the length of the bridge.
Answer: D. 20.8 km — ConceptFor uniform motion, distance equals speed multiplied by time, provided both quantities use compatible units. When speed is in kilometres per hour,…
- A.
17.6 km
- B.
25.1 km
- C.
25.5 km
- D.
20.8 km
Attempted by 58 students.
Show answer & explanation
Correct answer: D
Concept
For uniform motion, distance equals speed multiplied by time, provided both quantities use compatible units.
When speed is in kilometres per hour, convert time from minutes to hours before multiplying.
Application
Convert the time: 26 minutes = 26/60 hours.
Apply distance = speed × time: distance = 48 × 26/60 km.
Simplify: distance = 4 × 26/5 km = 104/5 km = 20.8 km.
Cross-check
Using time = distance ÷ speed, 20.8 ÷ 48 hour = 13/30 hour = 26 minutes, which reproduces the given crossing time.
Therefore, the bridge is 20.8 km long.