Answer:
The drum skin oscillates 20 times per second
Explanation:
The frequency of a note is dependent on the mechanical activities that occur when it is produced. A drum is beaten in this case. The oscillation of the drum skin transfers sound waves to the air particles which move at the same frequency before reaching our ears.
If the frequency of the sound wave is 20 Hz this means that the wave is oscillating 20 times in one second. For the drum to produce such a sound, the skin must have been oscillating at the same frequency of 20 oscillations per second too.
to prevent damage from landslides because construction engineers brace buildings in the earthquake zones
Answer:
Explanation:
Dissolving is importan because its a whole life sicle.
this is how desolving works:
1.an animal dies and starts desolving
2. when the animal desolves its fertilizes the ground and then grass grows
3. another animal comes and eats the grass
4. when that animal dies or gets killed by a predator it starts desolving
And then the 4 sicles repeat over and over.
It is B while cell walls do contain cellulose they do not contain hemicellulose
