How many seconds will a 500 metre long train take to cross a man walking with a speed of 3 km/hr in the direction of the moving train if the speed of the train is 63 km/hr?

Given Data

• Train length = 500 m
• Train speed = 63 km/hr
• Man walking in same direction = 3 km/hr
• Required: time for train to cross the man

Step 1: Relative speed (same direction ⇒ difference)
v_rel = 63 − 3 = 60 km/hr = 60 × (5/18) = 16.6667 m/s

Step 2: Time = distance ÷ speed
Distance = train length = 500 mt = 500 ÷ 16.6667 ≈ 30 s

Checks & Common Pitfalls

• Use difference of speeds for same-direction motion.
• Passing a man uses only the train length.

Final Answer
The train crosses the man in 30 s.