A train is moving at the speed of 72 km/hr. How many seconds will it take to cover a distance of 1400 m?

Options

A. 70
B. 80
C. 72
D. 84

Answer

To solve the problem of how long it will take for a train moving at 72 km/hr to cover a distance of 1400 meters, follow these steps:

### Step 1: Convert the speed from km/hr to m/s
The speed of the train is given as 72 km/hr. To convert this speed into meters per second (m/s), we use the conversion factor \( \frac{5}{18} \).

\[ \text{Speed in m/s} = \text{Speed in km/hr} \times \frac{5}{18} \]
\[ \text{Speed in m/s} = 72 \times \frac{5}{18} \]
\[ \text{Speed in m/s} = 72 \times \frac{5}{18} = 20 \text{ m/s} \]

### Step 2: Use the formula for distance
The relationship between distance, speed, and time is given by the formula:
\[ \text{Distance} = \text{Speed} \times \text{Time} \]
We can rearrange this formula to solve for time:
\[ \text{Time} = \frac{\text{Distance}}{\text{Speed}} \]

### Step 3: Substitute the known values
Now, we can substitute the known values into the formula. The distance is 1400 meters and the speed is 20 m/s.

\[ \text{Time} = \frac{1400 \text{ m}}{20 \text{ m/s}} \]
\[ \text{Time} = 70 \text{ seconds} \]

### Final Answer
The train will take **70 seconds** to cover a distance of 1400 meters.

---