A train running at the rate of 36 km/hr passes a standing man in 8 seconds. The length of the train is

Options

A. 45 metres
B. 28 metres
C. 80 metres
D. 48 metres

Answer

To find the length of the train that passes a standing man in 8 seconds while running at a speed of 36 km/hr, we can follow these steps:

### Step 1: Convert the speed from km/hr to m/s
To convert kilometers per hour (km/hr) to meters per second (m/s), we use the conversion factor:
\[ 1 \text{ km/hr} = \frac{5}{18} \text{ m/s} \]

So, for a speed of 36 km/hr:
\[ \text{Speed in m/s} = 36 \times \frac{5}{18} \]

### Step 2: Calculate the speed in m/s
Calculating the speed:
\[ \text{Speed in m/s} = 36 \times \frac{5}{18} = 36 \times \frac{5}{18} = 10 \text{ m/s} \]

### Step 3: Use the formula for distance
The distance covered by the train (which is equal to the length of the train) can be calculated using the formula:
\[ \text{Distance} = \text{Speed} \times \text{Time} \]

### Step 4: Substitute the values into the formula
Here, the speed is 10 m/s and the time is 8 seconds:
\[ \text{Distance} = 10 \text{ m/s} \times 8 \text{ s} \]

### Step 5: Calculate the distance
Calculating the distance:
\[ \text{Distance} = 10 \times 8 = 80 \text{ meters} \]

### Conclusion
The length of the train is **80 meters**.

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