Answer:
Part a)

Part b)

Explanation:
Part a)
Level of sound = 75 dB
now we know that

here we know that

now we have


Part b)
Intensity of sound wave is given as

here we know that

so we have


now we know



now we have


The continuous submarine mountain range which winds through all the oceans is called the mid-ocean <u>ridge.
</u>It is a form of a mountain which is found underwater, and it appeared there due to the movements of tectonic plates. It is responsible for the creation of new seafloor, meaning that the ground underwater changes constantly with the formation of these ridges. <u>
</u>
The normal reaction between the television and the table is
N = 12 × 9.8 m/s² = 117.6 Newtons
But the static coefficient of friction is μ = 0.83
When the television is about to slide on the table, the applied force should overcome the force due to static friction;
Thus; the applied force should be at least
F = μN
= 0.83 × 117.6 N
= 97.608 Newtons
Therefore; the minimum applied force will be 97.6 Newtons.
These actions are an example of feedback.
Given that the room has reached the desired temperature, there is no more need for it to be heated, at least until the temperature drops a bit. This is why the thermostat sends feedback about this situation to the heater, which immediately switches off until it is needed again.