The absolute zero in temperature refers to the minimal possible temperature. It is the temperature at which the molecules of a system stop moving, so it is a really useful reference point.
<h3>Why absolute zero can't be reached?</h3>
It would mean that we need to remove all the energy from a system, but to do this we need to interact with the system in some way, and by interacting with it we give it "some" energy.
Actually, from a quantum mechanical point of view, the absolute zero has a residual energy (so it is not actually zero) and it is called the "zero point". This happens because it must meet <u>Heisenberg's uncertainty principle</u>.
So yes, the absolute zero can't be reached, but there are really good approximations (At the moment there is a difference of about 150 nanokelvins between the absolute zero and the smallest temperature reached). Also, there are a lot of investigations near the absolute zero, like people that try to reach it or people that just need to work with really low temperatures, like in type I superconductors.
So, concluding, why does the concept exist?
- Because it is a reference point.
- It is the theoretical temperature at which the molecules stop moving, defining this as the <u>minimum possible temperature.</u>
If you want to learn more about the absolute zero, you can read:
brainly.com/question/3795971
Answer:

Explanation:
g = Acceleration due to gravity at sea level = 
R = Radius of Earth = 6371000 m
h = Altitude of observatory = 4205 m
Change in acceleration due to gravity due to change in altitude is given by

Weight at sea level

Weight at the given height

Change in weight 
Her weight reduces by
.
Answer:
to optimize the reliability of equipment and infrastructure;
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- to carry out prompt emergency repair of equipment and infrastructure so as to secure the best possible availability for production;
- to enhance, through modifications, extensions, or new low-cost items, the productivity of existing equipment or production capacity;
- to ensure the operation of equipment for production and for the distribution of energy and fluids;
- to improve operational safety;
- to train personnel in specific maintenance skills;
- to advise on the acquisition, installation and operation of machinery;
- to contribute to finished product quality;
- to ensure environmental protection.
Explanation:
pick whichever you want
Answer : The final velocity of the ball is, 12.03 m/s
Explanation :
By the 3rd equation of motion,

where,
s = distance covered by the object = 6.93 m
u = initial velocity = 2.99 m/s
v = final velocity = ?
a = acceleration = 
Now put all the given values in the above equation, we get the final velocity of the ball.


Thus, the final velocity of the ball is, 12.03 m/s
Answer:
ΔT= 11.94 °C
Explanation:
Given that
mass of water = 10 kh
Time t= 15 min
Heat lot from water = 400 KJ
Heat input to the water = 1 KW
Heat input the water= 1 x 15 x 60
=900 KJ
By heat balancing
Heat supply - heat rejected = Heat gain by water
As we know that heat capacity of water


Now by putting the values
900 - 400 = 10 x 4.187 x ΔT
So rise in temperature of water ΔT= 11.94 °C