a ship approaches a cliff its siren is sounded again and the echo is heard in the ship after 12seconds, 2.1 minutes later the siren was sounded again and the ec
Anglais
chykedavis2001
Question
a ship approaches a cliff its siren is sounded again and the echo is heard in the ship after 12seconds, 2.1 minutes later the siren was sounded again and the echo was heard 8seconds later . If the speed of sound in air is 340m/s calculate the velocity at which the ship was approaching the cliff
1 Réponse
-
1. Réponse olivierronat
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