A train 240 m long passes a pole in 24 seconds. How long will it take to pass a platform 650 m long?

Step 1: Find the speed of the train

The train passes a pole in 24 seconds. When a train passes a pole, it covers a distance equal to its own length.

Length of train = 240 m
Time = 24 seconds
Speed = Distance / Time = 240 / 24 = 10 m/s

Step 2: Total distance to cover while crossing a platform

When the train crosses a platform, it covers the distance equal to its own length + length of the platform.

Length of platform = 650 m
Total distance = 240 + 650 = 890 m

Step 3: Time taken to cross the platform

Speed = 10 m/s
Time = Distance / Speed = 890 / 10 = 89 seconds

Answer: 89 seconds

The train will take 89 seconds to cross the platform.

This type of question helps in understanding the concept of relative motion and how different lengths and times relate when a moving object passes a stationary object or structure like a platform.