Wave Behaviour Page 1 Page 2 Page 3 Page 4 Page 5 Page 6 Page 7 Page 8 Summary Test

Echoes. 
When you shout near mountains sound is reflected off the hills back to you. You hear this as an echo. 
Fishing boats use echoes to find the depth of the sea and also to detect shoals of fish. 
This is called 'sonar'. 
This fishing boat received the echo 50ms after sending it down from the bottom of the boat. 
The speed of sound in water is 1500m/s. 
The sound took half this time to reach the bottom. Time = 50 / 2 = 25ms = 0.025 seconds. 
(Remember; Distance Travelled = Speed x Time Taken) 
The depth of water = 1500 x 0.025 = 37.5m 
What do you think would happen if a shoal of fish swam under the boat?

Page 2Page 2


To play 'Guess the Room' and learn about echoes in rooms click here (1.6MB)

University of Salford, Salford, Greater Manchester M5 4WT, UK. Telephone: +44 (0)161 295 5000 | Fax: +44 (0) 161 295 5999
Contact D.Dewhurst@salford.ac.uk | accessibility statement | privacy statement
Page 4 Page 4      
Goto Teacher Area