Find the time taken by a train 150 m long, running at 60 km/hr in crossing a man standing on the platform.

Answer

To solve the problem of finding the time taken by a train 150 m long, running at 60 km/hr, to cross a man standing on the platform, we can follow these steps:

### Step-by-Step Solution:

1. **Convert the speed from km/hr to m/s**:
- The speed of the train is given as 60 km/hr.
- To convert km/hr to m/s, we use the conversion factor:
\[ 1 \text{ km/hr} = \frac{5}{18} \text{ m/s} \]
- Therefore,
\[ \text{Speed in m/s} = 60 \times \frac{5}{18} = \frac{300}{18} = \frac{50}{3} \text{ m/s} \]

2. **Identify the distance to be covered**:
- The distance the train needs to cover to completely cross the man is equal to the length of the train, which is 150 m.

3. **Use the formula for time**:
- The formula relating speed, distance, and time is:
\[ \text{Speed} = \frac{\text{Distance}}{\text{Time}} \quad \Rightarrow \quad \text{Time} = \frac{\text{Distance}}{\text{Speed}} \]
- Substituting the known values:
\[ \text{Time} = \frac{150 \text{ m}}{\frac{50}{3} \text{ m/s}} = 150 \times \frac{3}{50} \]

4. **Calculate the time**:
- Simplifying the expression:
\[ \text{Time} = \frac{150 \times 3}{50} = \frac{450}{50} = 9 \text{ seconds} \]

### Final Answer:
The time taken by the train to cross the man standing on the platform is **9 seconds**.