Correct Answer: 500
Explanation:
Step 1: Understand the given data
Step 2: Convert speed to meters per second
Speed in m/s = 78 × (5/18) = 21.67 m/s
Step 3: Use the formula: Distance = Speed × Time
Total distance covered in 60 seconds = 21.67 × 60 = 1300 meters
Step 4: Calculate the length of the tunnel
Distance = Length of train + Length of tunnel
1300 = 800 + Length of tunnel
Length of tunnel = 1300 - 800 = 500 meters
Answer: 500 meters
The length of the tunnel is 500 meters.
This problem demonstrates the use of basic motion formulas where a train covers its own length plus the length of the tunnel in the given time. Converting the train’s speed to m/s ensures consistency in units for calculating distance accurately.
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