In what time in seconds will a train 200 meter long cross an electric pole, if its speed be 144 km/hour?6 m25  s76 s5 s

1. Break Down the Problem

To find the time it takes for the train to cross an electric pole, we need to determine:

• The length of the train (200 meters).

• The speed of the train (144 km/h) which needs to be converted into meters per second (m/s).

• The formula to calculate time which is given by:

  $\text{Time} = \frac{\text{Distance}}{\text{Speed}}$

2. Relevant Concepts

• Conversion of Speed: To convert speed from kilometers per hour (km/h) to meters per second (m/s), we use the conversion factor:

  $1 \text{ km/h} = \frac{1000 \text{ meters}}{3600 \text{ seconds}} \approx 0.27778 \text{ m/s}$

3. Analysis and Detail

Step 1: Convert Speed Given speed is 144 km/h. To convert it to m/s:

$\text{Speed in m/s} = 144 \times \frac{1000}{3600} \approx 40 \text{ m/s}$

Step 2: Calculate Time Using the speed in m/s, we can calculate the time it takes to cross the pole. The distance to be covered is equal to the length of the train (200 meters).

$\text{Time} = \frac{\text{Distance}}{\text{Speed}} = \frac{200 \text{ m}}{40 \text{ m/s}} = 5 \text{ seconds}$

4. Verify and Summarize

The speed was converted correctly, and the calculations were correctly followed. Thus, the result is valid.

Final Answer

The train will cross the electric pole in 5 seconds.