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:
Work, U, is equal to the force times the distance:
U = F · r
Force needed to lift the weight, is equal to the weight: F = W = m · g
so:
U = m · g · r
= 20.4kg · 9.81 
· 1.50m
= 35.316 
= 35.316 W
Answer:
Bottom-up Estimation
Explanation:
Bottom-up estimation is a type of project cost estimation that considers the cost of individual project activities and finally sums them up or finds the aggregates. The summation gives an idea of what the entire project will cost.
This is an effective way of estimating the cost of a project as it evaluates the costs on a wholistic basis. It also considers the tiniest details during the estimation process. The process moves from the simpler details to the more complicated details.
9514 1404 393
Answer:
13/80
Explanation:
The product is ...
(1 3/10)×(1/8) = (13/10)×(1/8) = (13×1)/(10×8) = 13/80
