if there were no invention of machines then life would have been more difficult and simple works could be hard to do. Even now we are using our phones, sitting in a AC room interacting to eachother from different places. without the invention of machines simple things like transportation would have been difficult. There would be horses and donkey for the transportation. There would be no electricity,no internet, no transportation, not even c computers or mobile etc. The market for business will be smaller, the knowledge and news about world would be less.
so the problem would have been bigger than we can imagine. But one thing is that nature could survive lot more compared to what we have done till now by destroying nature.
Answer:
c. expanded polyurethane
Explanation:
Thermal performance of a building fabric is measured in terms of heat loss and is expressed as U-value or R-value. U-value is the rate of heat transferred through a structure divided by the difference in temperature across the structure with a unit of measurement of W/m²K.You can calculate the U-value of a by getting the reciprocal of the sum of thermal resistances , R, making the building material.
If you have the value of R, then U=1/R
Material size R U
plywood 1" 1.25 0.8
Poured concrete 2" 0.99 1.010
Expanded polyurethane 1" 6.5 0.1538
Asbestos shingles 1" 0.03 33.33
The material with lowest U-value is expanded polyurethane
The four distinct charges' combined potentials make up the potential in the square's center. The amount of the charge and the distance from the charge both affect the potential caused by a point charge.
Therefore, the center's total potential is V=4V1=ks4 q.
<h3>What is a charge?</h3>
Due to the physical characteristic of electric charge, charged material experiences a force when it is exposed to an electromagnetic field. An object that has no net charge is said to be neutral. Classical electrodynamics is the name given to an earlier theory of the interactions of charged particles.
You can have positive or negative electric charges (commonly carried by protons and electrons respectively). opposing charges attract one another whereas similar charges repel one another.
To learn more about charge from the given link:
brainly.com/question/9194793
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Because its expose to the wires inside that could electrify you.
Explanation:
Newton's second law of motion states F=ma which means force is equal to mass multiplied by acceleration which in simple terms means If you give mass force it will accelerate the concept of force in physics is any interaction that when unopposed will change the motion of an object.
