Some animals such as bats, use ultrasound waves to detect obstacles and objects around them. Ultrasounds are reflected of surfaces or objects and animals can listen to the echoes.
We can use a similar method to detect things we cannot see using ultrasound. Ships use sonar equipment to find the depth of the sea or to detect fish.
Ultrasound can be used to make images of things inside the body. One common use is to make images of unborn babies to see how the foetus is developing.
Distance can be calculated by using the following equation: distance (m) = speed (m/s) x time (s)
A ship detects a sonar pulse 3 seconds after it was emitted. The speed of sound in the sea water is 1500 m/s. 1. How far has the sound travelled? 2. How deep is the water?
4500m 2250m