Answer:
ADHD, also called attention-deficit disorder, is a behavior disorder, usually first diagnosed in childhood, that is characterized by inattention, impulsivity, and, in some cases, hyperactivity.
Explanation:
<h2>
Relationship Between Frequency and Period</h2>
The frequency and the period are inversely proportional.
where T is the period
<h2>Solving the Question</h2>
We're given:
- <em>v</em> = 340 m/s
- <em>f</em> = 1000 Hz
Because the frequency and the period are reciprocals of each other, we can find the period of the sound by finding the reciprocal of the frequency:

<h2>Answer</h2>

<span> In AC (alternating current) flow, like what comes out of your wall, the flow of electrons changes direction 60 times per second (50 times per second in Europe, China, etc). But in DC (direct current) flow, the average flow of electrons is in one direction only.
I hope it helped you</span>