In how much time a 280 m long train crosses a person. If speed of train is 63 km/hr.

Options

A. 12 sec
B. 16 sec
C. 20 sec
D. 24 sec

Answer

To solve the problem of how much time a 280 m long train takes to cross a person when the speed of the train is 63 km/hr, we can follow these steps:

### Step 1: Convert the speed from km/hr to m/s
The speed of the train is given as 63 km/hr. To convert this to meters per second (m/s), we use the conversion factor:
\[ 1 \text{ km/hr} = \frac{5}{18} \text{ m/s} \]
Thus, we calculate:
\[ \text{Speed in m/s} = 63 \times \frac{5}{18} \]
Calculating this gives:
\[ \text{Speed in m/s} = \frac{315}{18} = 17.5 \text{ m/s} \]

### Step 2: Identify the distance to be covered
The distance that the train needs to cover to completely cross the person is equal to the length of the train, which is 280 meters.

### Step 3: Use the formula for time
We know that:
\[ \text{Speed} = \frac{\text{Distance}}{\text{Time}} \]
Rearranging this formula to find time gives:
\[ \text{Time} = \frac{\text{Distance}}{\text{Speed}} \]
Substituting the values we have:
\[ \text{Time} = \frac{280 \text{ m}}{17.5 \text{ m/s}} \]

### Step 4: Calculate the time
Now we perform the division:
\[ \text{Time} = \frac{280}{17.5} = 16 \text{ seconds} \]

### Final Answer
The time taken for the train to cross the person is **16 seconds**.

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