Textbook Questions
| 1. |
Hearing sound
Difficulty: easy |
2
|
| 2. |
Echo receiver
Difficulty: medium |
2
|
| 3. |
Ultrasonic waves
Difficulty: medium |
2
|
| 4. |
Speed of sound in sea water
Difficulty: hard |
2
|
| 5. |
Sound absorbent
Difficulty: hard |
2
|