Question

ANSWER FAST............​

Answer 1

The answers to the given questions are as follows:

• SONAR stands for sound navigation and ranging
• The minimum distance at which the reflecting surface should be present for the occurrence of the echo is 16.5 m to 17 m
• Speed of sound is more in liquids than gases because molecules are more tightly packed.  
• Two good reflectors of sound are glass and brick
• Two bad reflectors of sound are carpets and curtains.
• Sound travels in all possible media.