A sound wave tracking along a canyon paths at 340 m/s. Find the total distance wrapped by the sound wave in exactly 25 seconds. MCQ with Answer and Explanation

Explanation:
Let total distance be 100 km. First part = 40 km; Time = 40 / 20 = 2 hours. Second part = 60 km; Time = 60 / 30 = 2 hours. Total distance = 100 km, Total time = 4 hours. Average speed = 100 / 4 = 25 km/h.

Explanation:
Relative speed = 72 - 12 = 60 km/h = 60 * (5/18) = 50/3 m/s. Length of train = Relative speed * Time = (50/3) * 12 = 200 meters.

Explanation:
Let total distance be 100 km. First section = 30 km; Time = 30 / 30 = 1 hour. Second section = 70 km; Time = 70 / 42 = 5/3 hours. Total time = 1 + 5/3 = 8/3 hours. Average speed = 100 / (8/3) = 300 / 8 = 37.5 km/h.