| I move faster in certain solids, but slower in certain gases. I am typically broken by objects with large masses. I can be used as for pleasure, practice, and even an alarm. If used excessively, I can cause harm.
What am I? |
 |
| I move faster in certain solids, but slower in certain gases. I am typically broken by objects with large masses. I can be used as for pleasure, practice, and even an alarm. If used excessively, I can cause harm.
What am I? |
|
