What is the time taken by a train 180 m long running at 72 km hr in crossing an electric pole?

The Swift Passage: How a Train Crosses an Electric Pole

We’ve all seen it: a blur of steel and color as a train streaks past a fixed point. But have you ever considered the math behind that fleeting moment? Let’s break down a common scenario – calculating the time it takes for a train to completely pass a stationary object, such as an electric pole.

Imagine a train, measuring a significant 180 meters from engine to caboose, barreling down the tracks at a steady 72 kilometers per hour. The task is simple: how long does it take for this train to completely cross an electric pole standing beside the tracks?

The key to solving this lies in understanding what “crossing” truly means. When the front of the train reaches the pole, the crossing begins. The crossing isn’t complete until the entire train has passed the pole. Therefore, the train effectively needs to travel the length of itself to fully clear the obstacle.

So, the distance the train needs to cover is 180 meters. But we also need to consider the speed, which is given in kilometers per hour. To make the calculations easier, we need to convert the speed into meters per second.

Here’s the conversion:

• 72 kilometers per hour is equal to 72 * 1000 meters per hour (since 1 kilometer = 1000 meters).
• To convert to meters per second, we further divide by 3600 (since there are 3600 seconds in an hour).
• Therefore, 72 km/hr = (72 * 1000) / 3600 meters per second = 20 meters per second.

Now we have all the pieces of the puzzle. We know the distance (180 meters) and the speed (20 meters per second). We can use the fundamental formula:

• Time = Distance / Speed

Plugging in the values:

• Time = 180 meters / 20 meters per second = 9 seconds.

Therefore, it takes the 180-meter train, traveling at 72 kilometers per hour, just 9 seconds to completely pass the electric pole.

This seemingly simple calculation highlights the interplay between speed, distance, and time. It demonstrates that even a large object like a train can pass a stationary point surprisingly quickly when moving at considerable speed. So, the next time you see a train whizzing by, remember the math behind that swift passage and appreciate the relationship between motion and time. The seemingly instantaneous crossing is, in reality, a carefully orchestrated dance of physics.