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.
The answer is that FRICTION PRODUCES HEAT.
Answer:
r1 -r2 = 3.75cm
Explanation:
Check the attached file for the solution
Answer:

Explanation:
Two identical sticky masses m are moving in the xy-plane, with their momenta at an angle of φ with one another. They are each moving at the same speed v when they collide at the origin of the coordinates and stick together. After the collision, the masses move at an angle −θ2 with respect to the +x axis at speed v2 .1. What was the angle φ?
from the principle of momentum
In a system of colliding bodies,we know that the total momentum before collision will equal to the total momentum after collision.
Take note that momentum is the product of mass and velocity
momentum before collision=momentum after collision
mass, m
u=initial velocity of the identical masses
v2=the common velocity after the collision
Note that the collision is inelastic , since they both moved with the same velocity
umcosφ+umcosφ=(m+m)v2cos−θ2
2mucosφ=2mv2cos−θ2

Answer:
<h2>12.5 N</h2>
Explanation:
The force acting on an object given it's mass and acceleration can be found by using the formula
force = mass × acceleration
From the question we have
force = 5 × 2.5
We have the final answer as
<h3>12.5 N</h3>
Hope this helps you