Calculating Poles Covered by Train

This solution calculates the total number of poles covered by a train based on its speed, travel time, and the distance between poles.

Step 1: Calculate Total Distance Covered

• Train Speed: $45 \text{ km/hr}$
• Travel Time: $4 \text{ hours}$
• Convert speed to meters per second (m/s): $45 \times \frac{1000}{3600} = 12.5 \text{ m/s}$
• Convert time to seconds (s): $4 \times 3600 = 14400 \text{ s}$
• Total Distance = Speed $\times$ Time
• Total Distance = $12.5 \text{ m/s} \times 14400 \text{ s} = 180000 \text{ m}$

Step 2: Calculate Number of Gaps Between Poles

• Distance between poles: $50 \text{ m}$
• Number of Gaps = Total Distance / Distance between poles
• Number of Gaps = $\frac{180000 \text{ m}}{50 \text{ m}} = 3600$

Step 3: Determine Total Number of Poles

• The train starts by crossing a pole.
• Total Poles = Number of Gaps + 1 (for the starting pole)
• Total Poles = $3600 + 1 = 3601$

Therefore, the train will cover 3601 poles.