Réponse :
Explications :
Bonjour
The time taken for the sound to travel from the ship to the cliff and back is 12 seconds. Since we only need the one-way distance, we'll divide this time by 2 so 6 seconds
The distance travelled by the sound is d₁ = 340 m/s × 6 s = 2040 meters
During the second instance, the time taken for the sound to travel from the ship to the cliff and back is 8 seconds. So a one way in 4 seconds
The distance travelled by the sound is d₂ = 340 m/s × 4 s = 1360 meters
During the time interval of 2.1 minutes (or 126 seconds), the ship approaches the cliff, reducing the distance between them. The change in distance is 2040-1360 = 680 meters
The velocity of the ship is 680 meters / 126 seconds = 5.4 m/s
