How long does a train 300 m long travelling at a speed of 54km/h take to cross a pole ?

Answer

To solve the problem of how long a train 300 m long, traveling at a speed of 54 km/h, takes to cross a pole, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Given Information:**
- Length of the train = 300 m
- Speed of the train = 54 km/h

2. **Convert the Speed from km/h to m/s:**
- To convert km/h to m/s, we use the conversion factor:
\[ 1 \text{ km/h} = \frac{1000 \text{ m}}{3600 \text{ s}} = \frac{1}{3.6} \text{ m/s} \]
- Therefore, to convert 54 km/h to m/s:
\[ 54 \text{ km/h} = 54 \times \frac{1000}{3600} \text{ m/s} \]
- Simplifying this:
\[ 54 \text{ km/h} = \frac{54000}{3600} \text{ m/s} = 15 \text{ m/s} \]

3. **Calculate the Time Taken to Cross the Pole:**
- The time taken to cross the pole can be calculated using the formula:
\[ \text{Time} = \frac{\text{Distance}}{\text{Speed}} \]
- Here, the distance is the length of the train (300 m) and the speed is 15 m/s:
\[ \text{Time} = \frac{300 \text{ m}}{15 \text{ m/s}} = 20 \text{ seconds} \]

4. **Conclusion:**
- Therefore, the train takes **20 seconds** to cross the pole.