Read the following case and answer the questions given below:
A SONAR device sends a sound pulse towards an underwater object. The pulse returns after \(1.2\ s\). The speed of sound in water is \(1500\ m/s\).
a. What principle is used by SONAR to determine the distance of an underwater object?
SONAR works on the principle of .
b. Calculate the total distance travelled by the sound pulse.
The sound pulse travels a total distance of \(=\) \(m\).
c. Calculate the distance between the SONAR device and the object.
The distance between the SONAR device and the object is \(=\) \(m\).
d. Why is the calculated distance in part (b) not equal to the distance of the object?
The distance calculated in part (b) represents the , because the sound travels from the . Therefore, the actual distance of the object is half of the total distance travelled by the sound.
e. Is the returning sound an example of an echo or reverberation? Give a reason.
The returning sound is an because the sound is and . The time taken for this reflected signal to return is used to calculate the distance of the object.