The whistling sound from the hearing aids represents that your hearing aids is working perfectly ad is known as the "feedback". So, the given statement is true.
Answer: Option A
<u>Explanation:</u>
It's often sounds irritating when a hearing aids of your grandpa or Grandma whistles. especially, when they put them out of their ears. Actually, this feedback sound from hearing aids occur when the sounds from the outer side bounces back to the microphone of the hearing aids.
The sound bounces back when it doesn't gets inside of your ear canal so that one can hear the sound through the hearing aid. When the sounds bounces back in the hearing aid, it get re-amplified and thus we hear the whistle sound which is known as the feedback of the device.
It's not always the feedback sound though. Sometimes the device whistles when it has some mechanical defect or when one hugs the other one or water gets inside and damaged the whole system.
Answer:
I think it’s the third one
Inertia is when a object in motion will stay in motion or in a standing still state unless acted upon by a unbalancing force.
Friction is when a object slows down because it is rubbing against another object.
If a object is sliding across a surface, theoretically, it would not stop but because it is on a flat surface it would experience friction, this will disperse some of the kinetic energy that it has thus slowing the object down eventually, after some time, to a stop.
Hope this helps! :)
Answer:

Explanation:
First, we are going to calculate the electrical potential in the point middle between the two charges
Remember that the electrical potential can be calculated as:

Where 
and it is satisfy the superposition principle, thus


The electrical potential at 10 cm from charge 1 is:


Since the work - energy theorem, we have:

where q is the electron's charge and m is the electron's mass
Therefore:

